code: public static SymbolType typeVariableOf(final String typeVariable, List<SymbolType> upperBounds) {
          return new SymbolType(upperBounds, typeVariable);
      }
docs: Builds a symbol for a type variable from a list of upper bounds.
  @param typeVariable the name of the variable
  @param upperBounds the upper bounds of the type variable
  @return a SymbolType that represents a variable (for generics)