I want to cast pyarrow table column from decimal(38,4) to int64.

col.cast(pa.int64())

Error:
File "pyarrow/table.pxi", line 443, in pyarrow.lib.Column.cast
File "pyarrow/error.pxi", line 89, in pyarrow.lib.check_status
pyarrow.lib.ArrowNotImplementedError: No cast implemented from decimal(38, 4) to int64

Python version : 3.6.5
Pyarrow version : 0.10.0

is it not implemented yet or I am not using it correctly? If not implemented yet, then any work around to cast columns?