Source

File: wp-includes/customize/class-wp-customize-selective-refresh.php

public function handle_error( $errno, $errstr, $errfile = null, $errline = null ) {
		$this->triggered_errors[] = array(
			'partial'      => $this->current_partial_id,
			'error_number' => $errno,
			'error_string' => $errstr,
			'error_file'   => $errfile,
			'error_line'   => $errline,
		);
		return true;
	}