WP_Image_Editor::get_extension( string $mime_type = null )

Source

File: wp-includes/class-wp-image-editor.php

protected static function get_extension( $mime_type = null ) {
		$extensions = explode( '|', array_search( $mime_type, wp_get_mime_types(), true ) );

		if ( empty( $extensions[0] ) ) {
			return false;
		}

		return $extensions[0];
	}