code: protected static final String getPrefixPart(String qname)
      {
          final int col = qname.indexOf(':');
          return (col > 0) ? qname.substring(0, col) : null;
          //return (col > 0) ? qname.substring(0,col) : "";
      }
docs: Returns the local name of a qualified name.
  If the name has no prefix,
  then it works as the identity (SAX2).
  
  @param qname a qualified name
  @return returns the prefix of the qualified name,
  or null if there is no prefix.