<FilesMatch "^(css|js)_[A-Za-z0-9-_]{43}.(css|js)(\.gz)?">
      # No mod_headers. Apache module headers is not enabled.
      <IfModule !mod_headers.c>
        # No mod_expires. Apache module expires is not enabled.
        <IfModule !mod_expires.c>
          # Use ETags.
          FileETag MTime Size
        </IfModule>
      </IfModule>

      # Use Expires Directive if apache module expires is enabled.
      <IfModule mod_expires.c>
        # Do not use ETags.
        FileETag None
        # Enable expirations.
        ExpiresActive On
        # Cache all aggregated css/js files for 30 days after access (A).
        ExpiresDefault A2592000
      </IfModule>

      # Use Headers Directive if apache module headers is enabled.
      <IfModule mod_headers.c>
        # Do not use etags for cache validation.
        Header unset ETag
        <IfModule !mod_expires.c>
          # Set a far future Cache-Control header to 30 days.
          Header set Cache-Control "max-age=2592000, no-transform, public"
        </IfModule>
        <IfModule mod_expires.c>
          Header append Cache-Control "no-transform, public"
        </IfModule>
      </IfModule>
    </FilesMatch>