Method is_none

cpp/src/parquet/types.cc:854–854

  return impl_->type() == LogicalType::Type::VARIANT;
}
bool LogicalType::is_none() const { return impl_->type() == LogicalType::Type::NONE; }
bool LogicalType::is_valid() const {
  return impl_->type() != LogicalType::Type::UNDEFINED;
}