code: static String getXADataSourceClassName(String vendorPropertiesPID) {
          String[] classNames = classNamesByPID.get(vendorPropertiesPID);
          return classNames == null ? null : classNames[2];
      }
docs: Infer the vendor implementation class name for javax.sql.XADataSource based on the PID of the vendor properties.
  A best effort is made for the known vendors.
  
  @param vendorPropertiesPID factory pid of the JDBC vendor properties.
  @return name of vendor implementation class for javax.sql.XADataSource. Null if unknown.