code: def unique(
      ar,
      return_index=False,
      return_inverse=False,
      return_counts=False,
      axis=None,
      *,
      size=None,
      fill_value=None,
  ):
      uniques = list(ivy.unique_all(ar, axis=axis))
      if size is not None:
          fill_value = (
              fill_value if fill_value is not None else 1
          )  # default fill_value 1
          pad_len = size - len(uniques[0])
          if pad_len > 0:
              # padding
              num_dims = len(uniques[0].shape) - 1
              padding = [(0, 0)] * num_dims + [(0, pad_len)]
              uniques[0] = ivy.pad(
                  uniques[0], padding, constant_values=fill_value
              )
              # padding the indices and counts with zeros
              for i in range(1, len(uniques)):
                  if i == 2:
                      continue
                  uniques[i] = ivy.pad(
                      uniques[i], padding[-1], constant_values=0
                  )
          else:
              for i in range(len(uniques)):
                  uniques[i] = uniques[i][..., :size]
      # constructing a list of bools for indexing
      bools = [return_index, return_inverse, return_counts]
      # indexing each element whose condition is True except for the values
      uniques = [uniques[0]] + [
          uni for idx, uni in enumerate(uniques[1:]) if bools[idx]
      ]
      return uniques[0] if len(uniques) == 1 else uniques
  
imports: import logging
  import ivy
  from ivy.functional.frontends.jax.func_wrapper import to_ivy_arrays_and_back
  from ivy.functional.frontends.numpy.func_wrapper import from_zero_dim_arrays_to_scalar
  from ivy.func_wrapper import with_supported_device_and_dtypes, with_unsupported_dtypes
label_desc: Use image node_id 16 for calling a global function with example usage: unique(ar, return_index, return_inverse, return_counts, axis) and returns: unknown