code: public org.inferred.freebuilder.processor.property.Property.Builder setNullableBoxedType(
        TypeMirror boxedType) {
      if (boxedType != null) {
        return setBoxedType(boxedType);
      } else {
        return clearBoxedType();
      }
    }
docs: Sets the value to be returned by {@link
  org.inferred.freebuilder.processor.property.Property#getBoxedType()}.
  
  @return this {@code Builder} object