Method AppendNull

cpp/src/arrow/array/builder_primitive.h:120–125

\brief Append a single null element

  /// \brief Append a single null element
  Status AppendNull() final {
    ARROW_RETURN_NOT_OK(Reserve(1));
    data_builder_.UnsafeAppend(value_type{});  // zero
    UnsafeAppendToBitmap(false);
    return Status::OK();
  }

  /// \brief Append a empty element
  Status AppendEmptyValue() final {