@Override
            public String visitPrimitive(PrimitiveType primitiveType, Void v) {
              return types.boxedClass(primitiveType).getSimpleName().toString();
            }
Returns a valid Java identifier for method or variable of type {@code type}.
value/src/main/java/com/google/auto/value/extension/toprettystring/processor/ToPrettyStringExtension.java