code: public static <T extends TypeDefinition> ElementMatcher.Junction<T> isVariable(String symbol) {
          return isVariable(named(symbol));
      }
docs: Matches a type variable with the given name.
  
  @param symbol The name of the type variable to be match.
  @param <T>    The type of the matched object.
  @return A matcher that matches type variables with the given name.