rajvirsaggu

This is the line

/*
			 * Merge post types with any that already declared their support
			 * for post thumbnails.
			 */
			if ( is_array( $args[0] ) && isset( $_wp_theme_features['post-thumbnails'] ) ) {
				$args[0] = array_unique( array_merge( $_wp_theme_features['post-thumbnails'][0], $args[0] ) );
			}