Perform Function On Any Site of Multisite Network

/**
 *  Perform any function on any site on the network
 *
 *  @param    integer         $site_id   site on which to perform the function
 *  @param    string|array    $action    function name to perform
 *  @param    array           $args      parameters passed as an indexed array
 *  @return
 */
function do_network_request( $site_id, $action, $args = array() ) {

   switch_to_blog( $site_id );

      if ( ( is_string( $action ) && function_exists( $action ) ) || ( is_array( $action ) && method_exists( ...$action ) ) )
         $result = call_user_func( $action, ...$args );
      else
         $result = NULL;

   restore_current_blog();

   return $result;

} // end do_network_request

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