Write the FieldTable to the file-like object `out`.

        .. note::

            Advanced usage only. You will typically never need to call this
            method as it will be called for you when saving a ClassFile.

        :param out: Any file-like object providing `write()`

def pack(self, out: IO):
        """
        Write the FieldTable to the file-like object `out`.

        .. note::

            Advanced usage only. You will typically never need to call this
            method as it will be called for you when saving a ClassFile.

        :param out: Any file-like object providing `write()`
        """
        out.write(pack('>H', len(self)))
        for field in self._table:
            field.pack(out)