code: private static int checkTypeVariableSignature(final String signature,
              int pos) {
          // TypeVariableSignature:
          // T Identifier ;
  
          pos = checkChar('T', signature, pos);
          pos = checkIdentifier(signature, pos);
          return checkChar(';', signature, pos);
      }
docs: Checks a type variable signature.
  
  @param signature
  a string containing the signature that must be checked.
  @param pos
  index of first character to be checked.
  @return the index of the first character after the checked part.