code: private Type parseBracketedType(EnclosingScope scope) {
  		int start = index;
  		match(LeftBrace);
  		Type type = parseType(scope);
  		match(RightBrace);
  		return type;
  	}
docs: Parse a bracketed type, which is of the form:
  
  <pre>
  BracketedType ::= '(' Type ')'
  </pre>
  
  @return