code: private String getClassName(final TypeMirror t) {
          String res = null;
  
          if (t instanceof DeclaredType) {
              final DeclaredType dt = (DeclaredType) t;
              res = ((TypeElement) dt.asElement()).getQualifiedName().toString();
              if (!dt.getTypeArguments().isEmpty()) {
                  res += "<";
                  boolean first = true;
                  for (final TypeMirror tm : dt.getTypeArguments()) {
                      if (first) {
                          first = false;
                      } else {
                          res += ",";
                      }
                      res += getClassName(tm);
                  }
                  res += ">";
              }
  
          } else if (t instanceof PrimitiveType) {
              res = ((PrimitiveType) t).toString();
          }
  
          return res;
      }
docs: Gets the class name.
  
  @param t the t
  @return the class name