code: def solve(
      b: Union[torch.Tensor, ComplexTensor],
      a: Union[torch.Tensor, ComplexTensor],
  ):
      """Solve the linear equation ax = b."""
      # NOTE: Do not mix ComplexTensor and torch.complex in the input!
      # NOTE (wangyou): Until PyTorch 1.9.0, torch.solve does not support
      # mixed input with complex and real tensors.
      if isinstance(a, ComplexTensor) or isinstance(b, ComplexTensor):
          if isinstance(a, ComplexTensor) and isinstance(
              b, ComplexTensor
          ):
              return FC.solve(b, a, return_LU=False)
          else:
              return matmul(inverse(a), b)
      elif torch.is_complex(a) or torch.is_complex(b):
          if torch.is_complex(a) and torch.is_complex(b):
              return torch.linalg.solve(a, b)
          else:
              return matmul(inverse(a), b)
      else:
          return torch.linalg.solve(a, b)
  
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 14 for calling a global function with example usage: solve(b, a) and returns: FC, matmul, torch, torch, matmul