code: def diff(input, n=1, dim=-1, prepend=None, append=None):
      return ivy.diff(
          input, n=n, axis=dim, prepend=prepend, append=append, out=None
      )
  
imports: import ivy
  from ivy.func_wrapper import with_unsupported_dtypes, with_supported_dtypes
  from ivy.functional.frontends.torch.func_wrapper import to_ivy_arrays_and_back
  from ivy.functional.frontends.torch import promote_types_of_torch_inputs
  import ivy.functional.frontends.torch
label_desc: Use image node_id 19 for calling a global function with example usage: diff(input, n, dim, prepend, append) and returns: ivy