@internal<EOL><INDENT>def _loadFromUnion(self, dtype: HdlType, bitAddr: int) -> int:<DEDENT>
for field in dtype.fields.values():<EOL><INDENT>ch = TransTmpl(field.dtype, <NUM_LIT:0>, parent=self, origin=field)<EOL>self.children.append(ch)<EOL><DEDENT>return bitAddr + dtype.bit_length()<EOL>
Parse HUnion type to this transaction template instance

:return: address of it's end