code: def _test_store_helper(self, xp, dtype, fft_func):
      fft = getattr(xp.fft, fft_func)
      code = _store_callback
      if dtype == np.complex64:
          if fft_func != "irfft":
              types = ("x.y", "cufftComplex", "cufftCallbackStoreC")
          else:
              types = ("x", "cufftReal", "cufftCallbackStoreR")
      elif dtype == np.complex128:
          if fft_func != "irfft":
              types = (
                  "x.y",
                  "cufftDoubleComplex",
                  "cufftCallbackStoreZ",
              )
          else:
              types = ("x", "cufftDoubleReal", "cufftCallbackStoreD")
      elif dtype == np.float32:
          types = ("x.y", "cufftComplex", "cufftCallbackStoreC")
      elif dtype == np.float64:
          types = ("x.y", "cufftDoubleComplex", "cufftCallbackStoreZ")
      cb_store = _set_store_cb(code, *types)
  
      a = testing.shaped_random(self.shape, xp, dtype)
      if xp is np:
          out = fft(a, n=self.n, norm=self.norm)
          if fft_func != "irfft":
              out.imag /= 3.8
              if dtype in (np.float32, np.complex64):
                  out = out.astype(np.complex64)
          else:
              out /= 3.8
              if dtype in (np.float32, np.complex64):
                  out = out.astype(np.float32)
      else:
          with use_temporary_cache_dir():
              with xp.fft.config.set_cufft_callbacks(cb_store=cb_store):
                  out = fft(a, n=self.n, norm=self.norm)
  
      return out
  
imports: import contextlib
  import string
  import sys
  import tempfile
  from unittest import mock
  import numpy
  import pytest
  import cupy
  from cupy import testing
label_desc: Use image node_id 6 for calling the Test1dCallbacks obj's underlying member method code with example usage: obj._test_store_helper(xp, dtype, fft_func) and returns: out