code: public static Attributes addLocationAttributes(Locator locator, Attributes attrs) {
  		if (locator == null || attrs.getIndex(URI, SRC_ATTR) != -1) {
  			return attrs;
  		}
  		AttributesImpl newAttrs = attrs instanceof AttributesImpl ? (AttributesImpl) attrs : new AttributesImpl(attrs);
  		
  		return newAttrs;
  	}
docs: Add location attributes to a set of SAX attributes.
  
  @param locator
  the <code>Locator</code> (can be null)
  @param attrs
  the <code>Attributes</code> where locator information should
  be added
  @return Location enabled Attributes.