code: def _is_signed_int(self, x):
      return isinstance(x, int) or x.dtype.kind == "i"
  
imports: import unittest
  import numpy
  from cupy import testing
  from cupy_tests.core_tests.fusion_tests import fusion_utils
label_desc: Use image node_id 2 for calling the TestFusionArrayBitwiseOperator obj's underlying member method code with example usage: obj._is_signed_int(x) and returns: unknown