code: protected function parse_message() {
  
  		if ( empty( $this->args['message'] ) ) {
  			return null;
  		}
  
  		$like = esc_sql( $this->args['message'] );
  
  		return new Where( 'message', 'LIKE', "%{$like}%" );
  	}
docs: Parse a partial search for a message.
  
  @since 1.0
  
  @return Where|null