WPの関数：_deprecated_argument()

function__deprecated_argument.php

<? php
  function _deprecated_argument( $function, $version, $message = null ) {
 
    /**
     * Fires when a deprecated argument is called.
     *
     * @since 3.0.0
     *
     * @param string $function The function that was called.
     * @param string $message  A message regarding the change.
     * @param string $version  The version of WordPress that deprecated the argument used.
     */
    // 引数をもとにアクションフックに登録している関数を実行
    do_action( 'deprecated_argument_run', $function, $message, $version );
 
    /**
     * Filters whether to trigger an error for deprecated arguments.
     *
     * @since 3.0.0
     *
     * @param bool $trigger Whether to trigger the error for deprecated arguments. Default true.
     */
  　// デバッグモードまたは、deprecated_argument_trigger_errorが登録されている場合
    if ( WP_DEBUG && apply_filters( 'deprecated_argument_trigger_error', true ) ) {
        if ( function_exists( '__' ) ) {
            if ( ! is_null( $message ) ) {
                /* translators: 1: PHP function name, 2: version number, 3: optional message regarding the change */
                trigger_error( sprintf( __( '%1$s was called with an argument that is <strong>deprecated</strong> since version %2$s! %3$s' ), $function, $version, $message ) );
            } else {
                /* translators: 1: PHP function name, 2: version number */
                trigger_error( sprintf( __( '%1$s was called with an argument that is <strong>deprecated</strong> since version %2$s with no alternative available.' ), $function, $version ) );
            }
        } else {
            if ( ! is_null( $message ) ) {
                trigger_error( sprintf( '%1$s was called with an argument that is <strong>deprecated</strong> since version %2$s! %3$s', $function, $version, $message ) );
            } else {
                trigger_error( sprintf( '%1$s was called with an argument that is <strong>deprecated</strong> since version %2$s with no alternative available.', $function, $version ) );
            }
        }
    }
}

https://developer.wordpress.org/reference/functions/_deprecated_argument/