code: @Override
      public String toImplementationClassName(final String className) {
          final String implementationClassName = interfaceToImplementationMap.get(className);
          if (implementationClassName != null) {
              return implementationClassName;
          }
          final int index = className.lastIndexOf('.');
          if (index < 0) {
              return getImplementationPackageName() + "." + className + implementationSuffix;
          }
          return className.substring(0, index) + "." + getImplementationPackageName() + "." + className.substring(index + 1)
                  + implementationSuffix;
      }
docs: ========================