anitized.
 */
function sanitize_category_field( $field, $value, $cat_id, $context ) {
	return sanitize_term_field( $field, $value, $cat_id, 'category', $context );
}

/* Tags */

/**
 * Retrieves all post tags.
 *
 * @since 2.3.0
 *
 * @param string|array $args {
 *     Optional. Arguments to retrieve tags. See get_terms() for additional options.
 *
 *     @type string $taxonomy Taxonomy to retrieve terms for. Default 'post_tag'.
 * }
 * @return WP_Term[]|int|WP_Error Array of 'post_tag' term objects, a count thereof,
 *                                or WP_Error if any of the taxonomies do not exist.
 */
function get_tags( $args = '' ) {
	$defaults = array( 'taxonomy' => 'post_tag' );
	$args     = wp_parse_args( $args, $defaults );

	$tags = get_terms( $args );

	if ( empty( $tags ) ) {
		$tags = array();
	} else {
		/**
		 * Filters the array of term objects returned for the 'post_tag' taxonomy.
		 *
		 * @since 2.3.0
		 *
		 * @param WP_Term[]|int|WP_Error $tags Array of 'post_tag' term objects, a count thereof,
		 *                                     or WP_Error if any of the taxonomies do not exist.
		 * @param array                  $args An array of arguments. @see get_terms()
		 */
		$tags = apply_filters( 'get_tags', $tags, $args );
	}

	return $tags;
}

/**
 * Retrieves a post tag by tag ID or tag object.
 *
 * If you pass the $tag parameter an object, which is assumed to be the tag row
 * object retrieved from the database, it will cache the tag data.
 *
 * If you pass $tag an integer of the tag ID, then that tag will be retrieved
 * from the database, if it isn't already cached, and passed back.
 *
 * If you look at get_term(), both types will be passed through several filters
 * and finally sanitized based on the $filter parameter value.
 *
 * @since 2.3.0
 *
 * @param int|WP_Term|object $tag    A tag ID or object.
 * @param string             $output Optional. The required return type. One of OBJECT, ARRAY_A, or ARRAY_N, which
 *                                   correspond to a WP_Term object, an associative array, or a numeric array,
 *                                   respectively. Default OBJECT.
 * @param string             $filter Optional. How to sanitize tag fields. Default 'raw'.
 * @return WP_Term|array|WP_Error|null Tag data in type defined by $output parameter.
 *                                     WP_Error if $tag is empty, null if it does not exist.
 */
function get_tag( $tag, $output = OBJECT, $filter = 'raw' ) {
	return get_term( $tag, 'post_tag', $output, $filter );
}

/* Cache */

/**
 * Removes the category cache data based on ID.
 *
 * @since 2.1.0
 *
 * @param int $id Category ID
 */
function clean_category_cache( $id ) {
	clean_term_cache( $id, 'category' );
}

/**
 * Updates category structure to old pre-2.3 from new taxonomy structure.
 *
 * This function was added for the taxonomy support to update the new category
 * structure with the old category one. This will maintain compatibility with
 * plugins and themes which depend on the old key or property names.
 *
 * The parameter should only be passed a variable and not create the array or
 * object inline to the parameter. The reason for this is that parameter is
 * passed by reference and PHP will fail unless it has the variable.
 *
 * There is no return value, because everything is updated on the variable you
 * pass to it. This is one of the features with using pass by reference in PHP.
 *
 * @since 2.3.0
 * @since 4.4.0 The `$category` parameter now also accepts a WP_Term object.
 * @access private
 *
 * @param array|object|WP_Term $category Category row object or array.
 */
function _make_cat_compat( &$category ) {
	if ( is_object( $category ) && ! is_wp_error( $category ) ) {
		$category->cat_ID               = $category->term_id;
		$category->category_count       = $category->count;
		$category->category_description = $category->description;
		$category->cat_name             = $category->name;
		$category->category_nicename    = $category->slug;
		$category->category_parent      = $category->parent;
	} elseif ( is_array( $category ) && isset( $category['term_id'] ) ) {
		$category['cat_ID']               = &$category['term_id'];
		$category['category_count']       = &$category['count'];
		$category['category_description'] = &$category['description'];
		$category['cat_name']             = &$category['name'];
		$category['category_nicename']    = &$category['slug'];
		$category['category_parent']      = &$category['parent'];
	}
}
because nothing is blocked.
		if ( ! defined( 'WP_HTTP_BLOCK_EXTERNAL' ) || ! WP_HTTP_BLOCK_EXTERNAL ) {
			return false;
		}

		$check = parse_url( $uri );
		if ( ! $check ) {
			return true;
		}

		$home = parse_url( get_option( 'siteurl' ) );

		// Don't block requests back to ourselves by default.
		if ( 'localhost' === $check['host'] || ( isset( $home['host'] ) && $home['host'] === $check['host'] ) ) {
			/**
			 * Filters whether to block local HTTP API requests.
			 *
			 * A local request is one to `localhost` or to the same host as the site itself.
			 *
			 * @since 2.8.0
			 *
			 * @param bool $block Whether to block local requests. Default false.
			 */
			return apply_filters( 'block_local_requests', false );
		}

		if ( ! defined( 'WP_ACCESSIBLE_HOSTS' ) ) {
			return true;
		}

		static $accessible_hosts = null;
		static $wildcard_regex   = array();
		if ( null === $accessible_hosts ) {
			$accessible_hosts = preg_split( '|,\s*|', WP_ACCESSIBLE_HOSTS );

			if ( str_contains( WP_ACCESSIBLE_HOSTS, '*' ) ) {
				$wildcard_regex = array();
				foreach ( $accessible_hosts as $host ) {
					$wildcard_regex[] = str_replace( '\*', '.+', preg_quote( $host, '/' ) );
				}
				$wildcard_regex = '/^(' . implode( '|', $wildcard_regex ) . ')$/i';
			}
		}

		if ( ! empty( $wildcard_regex ) ) {
			return ! preg_match( $wildcard_regex, $check['host'] );
		} else {
			return ! in_array( $check['host'], $accessible_hosts, true ); // Inverse logic, if it's in the array, then don't block it.
		}

	}

	/**
	 * Used as a wrapper for PHP's parse_url() function that handles edgecases in < PHP 5.4.7.
	 *
	 * @deprecated 4.4.0 Use wp_parse_url()
	 * @see wp_parse_url()
	 *
	 * @param string $url The URL to parse.
	 * @return bool|array False on failure; Array of URL components on success;
	 *                    See parse_url()'s return values.
	 */
	protected static function parse_url( $url ) {
		_deprecated_function( __METHOD__, '4.4.0', 'wp_parse_url()' );
		return wp_parse_url( $url );
	}

	/**
	 * Converts a relative URL to an absolute URL relative to a given URL.
	 *
	 * If an Absolute URL is provided, no processing of that URL is done.
	 *
	 * @since 3.4.0
	 *
	 * @param string $maybe_relative_path The URL which might be relative.
	 * @param string $url                 The URL which $maybe_relative_path is relative to.
	 * @return string An Absolute URL, in a failure condition where the URL cannot be parsed, the relative URL will be returned.
	 */
	public static function make_absolute_url( $maybe_relative_path, $url ) {
		if ( empty( $url ) ) {
			return $maybe_relative_path;
		}

		$url_parts = wp_parse_url( $url );
		if ( ! $url_parts ) {
			return $maybe_relative_path;
		}

		$relative_url_parts = wp_parse_url( $maybe_relative_path );
		if ( ! $relative_url_parts ) {
			return $maybe_relative_path;
		}

		// Check for a scheme on the 'relative' URL.
		if ( ! empty( $relative_url_parts['scheme'] ) ) {
			return $maybe_relative_path;
		}

		$absolute_path = $url_parts['scheme'] . '://';

		// Schemeless URLs will make it this far, so we check for a host in the relative URL
		// and convert it to a protocol-URL.
		if ( isset( $relative_url_parts['host'] ) ) {
			$absolute_path .= $relative_url_parts['host'];
			if ( isset( $relative_url_parts['port'] ) ) {
				$absolute_path .= ':' . $relative_url_parts['port'];
			}
		} else {
			$absolute_path .= $url_parts['host'];
			if ( isset( $url_parts['port'] ) ) {
				$absolute_path .= ':' . $url_parts['port'];
			}
		}

		// Start off with the absolute URL path.
		$path = ! empty( $url_parts['path'] ) ? $url_parts['path'] : '/';

		// If it's a root-relative path, then great.
		if ( ! empty( $relative_url_parts['path'] ) && '/' === $relative_url_parts['path'][0] ) {
			$path = $relative_url_parts['path'];

			// Else it's a relative path.
		} elseif ( ! empty( $relative_url_parts['path'] ) ) {
			// Strip off any file components from the absolute path.
			$path = substr( $path, 0, strrpos( $path, '/' ) + 1 );

			// Build the new path.
			$path .= $relative_url_parts['path'];

			// Strip all /path/../ out of the path.
			while ( strpos( $path, '../' ) > 1 ) {
				$path = preg_replace( '![^/]+/\.\./!', '', $path );
			}

			// Strip any final leading ../ from the path.
			$path = preg_replace( '!^/(\.\./)+!', '', $path );
		}

		// Add the query string.
		if ( ! empty( $relative_url_parts['query'] ) ) {
			$path .= '?' . $relative_url_parts['query'];
		}

		// Add the fragment.
		if ( ! empty( $relative_url_parts['fragment'] ) ) {
			$path .= '#' . $relative_url_parts['fragment'];
		}

		return $absolute_path . '/' . ltrim( $path, '/' );
	}

	/**
	 * Handles an HTTP redirect and follows it if appropriate.
	 *
	 * @since 3.7.0
	 *
	 * @param string $url      The URL which was requested.
	 * @param array  $args     The arguments which were used to make the request.
	 * @param array  $response The response of the HTTP request.
	 * @return array|false|WP_Error An HTTP API response array if the redirect is successfully followed,
	 *                              false if no redirect is present, or a WP_Error object if there's an error.
	 */
	public static function handle_redirects( $url, $args, $response ) {
		// If no redirects are present, or, redirects were not requested, perform no action.
		if ( ! isset( $response['headers']['location'] ) || 0 === $args['_redirection'] ) {
			return false;
		}

		// Only perform redirections on redirection http codes.
		if ( $response['response']['code'] > 399 || $response['response']['code'] < 300 ) {
			return false;
		}

		// Don't redirect if we've run out of redirects.
		if ( $args['redirection']-- <= 0 ) {
			return new WP_Error( 'http_request_failed', __( 'Too many redirects.' ) );
		}

		$redirect_location = $response['headers']['location'];

		// If there were multiple Location headers, use the last header specified.
		if ( is_array( $redirect_location ) ) {
			$redirect_location = array_pop( $redirect_location );
		}

		$redirect_location = WP_Http::make_absolute_url( $redirect_location, $url );

		// POST requests should not POST to a redirected location.
		if ( 'POST' === $args['method'] ) {
			if ( in_array( $response['response']['code'], array( 302, 303 ), true ) ) {
				$args['method'] = 'GET';
			}
		}

		// Include valid cookies in the redirect process.
		if ( ! empty( $response['cookies'] ) ) {
			foreach ( $response['cookies'] as $cookie ) {
				if ( $cookie->test( $redirect_location ) ) {
					$args['cookies'][] = $cookie;
				}
			}
		}

		return wp_remote_request( $redirect_location, $args );
	}

	/**
	 * Determines if a specified string represents an IP address or not.
	 *
	 * This function also detects the type of the IP address, returning either
	 * '4' or '6' to represent an IPv4 and IPv6 address respectively.
	 * This does not verify if the IP is a valid IP, only that it appears to be
	 * an IP address.
	 *
	 * @link http://home.deds.nl/~aeron/regex/ for IPv6 regex.
	 *
	 * @since 3.7.0
	 *
	 * @param string $maybe_ip A suspected IP address.
	 * @return int|false Upon success, '4' or '6' to represent an IPv4 or IPv6 address, false upon failure.
	 */
	public static function is_ip_address( $maybe_ip ) {
		if ( preg_match( '/^\d{1,3}\.\d{1,3}\.\d{1,3}\.\d{1,3}$/', $maybe_ip ) ) {
			return 4;
		}

		if ( str_contains( $maybe_ip, ':' ) && preg_match( '/^(((?=.*(::))(?!.*\3.+\3))\3?|([\dA-F]{1,4}(\3|:\b|$)|\2))(?4){5}((?4){2}|(((2[0-4]|1\d|[1-9])?\d|25[0-5])\.?\b){4})$/i', trim( $maybe_ip, ' []' ) ) ) {
			return 6;
		}

		return false;
	}

}