code: def convert_to_complex_array(x_float2, dtype=np.complex64):
      x_real = x_float2[..., 0]
      x_imag = x_float2[..., 1]
      x_complex = x_real + 1j * x_imag
      return x_complex
  
imports: from nnabla.utils import nnabla_pb2
  from six.moves import filter
  import copy
  import nnabla
  import nnabla.ext_utils
  import nnabla.functions
  import nnabla.utils.converter
  import nnabla.dtypes
  from nnabla.testing import assert_allclose
  import numpy
  import numpy
  import platform
label_desc: Use image node_id 21 for calling a global function with example usage: convert_to_complex_array(x_float2, dtype) and returns: x_complex