import _testcapi

code = """
import _codecs_jp
import _multibytecodec

class IncrementalEncoder(_multibytecodec.MultibyteIncrementalEncoder):
    codec = _codecs_jp.getcodec('cp932')

enc = IncrementalEncoder()
"""

print("main")
exec(code)

print("sub")
_testcapi.run_in_subinterp(code)