Source

File: wp-includes/pomo/entry.php

function merge_with( &$other ) {
			$this->flags      = array_unique( array_merge( $this->flags, $other->flags ) );
			$this->references = array_unique( array_merge( $this->references, $other->references ) );
			if ( $this->extracted_comments != $other->extracted_comments ) {
				$this->extracted_comments .= $other->extracted_comments;
			}

		}