Docs
chromia.com

OBJECT

transfer_extensions_state

object transfer_extensions_state {
 mutable is_before_transfer_called: boolean = 0;
 mutable before_transfer_from: byte_array = x"";
 mutable before_transfer_to: byte_array = x"";
 mutable before_transfer_asset: byte_array = x"";
 mutable before_transfer_amount: big_integer = 0L;
 mutable is_after_transfer_called: boolean = 0;
 mutable after_transfer_from: byte_array = x"";
 mutable after_transfer_to: byte_array = x"";
 mutable after_transfer_asset: byte_array = x"";
 mutable after_transfer_amount: big_integer = 0L;
}
Source