code: def to_complex(c):
      # Convert to torch native complex
      if isinstance(c, ComplexTensor):
          c = c.real + 1j * c.imag
          return c
      elif torch.is_complex(c):
          return c
      else:
          return torch.view_as_complex(c)
  
file_path: espnet/espnet2/enh/layers/complex_utils.py
imports: from typing import Sequence, Tuple, Union
  import torch
  from torch_complex import functional
  from torch_complex.tensor import ComplexTensor
label_desc: Use image node_id 4 for calling a global function with example usage: to_complex(c) and returns: c, c, torch