code: public Datatype.Builder setValueType(TypeClass valueType) {
      this.valueType = Objects.requireNonNull(valueType);
      _unsetProperties.remove(Property.VALUE_TYPE);
      return (Datatype.Builder) this;
    }
docs: Sets the value to be returned by {@link Datatype#getValueType()}.
  
  @return this {@code Builder} object
  @throws NullPointerException if {@code valueType} is null