Remove unneeded import.
@@ -13,7 +13,6 @@ from kgtk.cli_argparse import KGTKArgumentParser
from kgtk.io.kgtkreader import KgtkReader, KgtkReaderOptions
from kgtk.io.kgtkwriter import KgtkWriter
from kgtk.join.kgtkexpand import KgtkExpand
-from kgtk.utils.argparsehelpers import optional_bool
from kgtk.value.kgtkvalueoptions import KgtkValueOptions
def parser():
