code: public static Identity createExtendedIdentifier(String namespaceUri, String namespacePrefix, String identifierName) {
  		return createExtendedIdentifier(namespaceUri, namespacePrefix, identifierName, null, "");
  	}
docs: Creates an Extended Identifier; uses an empty string for the administrativeDomain attribute and does not add an
  attribute <i>name</i>.
  
  @param namespaceUri
  URI of the namespace of the inner XML of the Extended Identifier
  @param namespacePrefix
  prefix of the namespace of the inner XML of the Extended Identifier
  @param identifierName
  the name value of the Extended Identifier (will be the root node of the inner XML)
  @return an {@link Identity} instance encapsulating the Extended Identifier