code: def merge(
      *structures: Mapping[str, Mapping[str, Any]],
      check_duplicates: bool = False,
  ) -> MutableMapping[str, MutableMapping[str, Any]]:
      """Merges multiple input structures.
  
      >>> weights = {'linear': {'w': None}}
      >>> biases = {'linear': {'b': None}}
      >>> hk.data_structures.merge(weights, biases)
      {'linear': {'w': None, 'b': None}}
  
      When structures are not disjoint the output will contain the value from the
      last structure for each path:
  
      >>> weights1 = {'linear': {'w': 1}}
      >>> weights2 = {'linear': {'w': 2}}
      >>> hk.data_structures.merge(weights1, weights2)
      {'linear': {'w': 2}}
  
      Note: returns a new structure not a view.
  
      Args:
        *structures: One or more structures to merge.
        check_duplicates: If True, a ValueError will be thrown if an array is
          found in multiple structures but with a different shape and dtype.
  
      Returns:
        A single structure with an entry for each path in the input structures.
      """
      array_like = lambda o: hasattr(o, "shape") and hasattr(o, "dtype")
      shaped = lambda a: (a.shape, a.dtype) if array_like(a) else None
      fmt = (
          lambda a: utils.format_array(a) if array_like(a) else repr(a)
      )
  
      out = collections.defaultdict(dict)
      for structure in structures:
          for module_name, name, value in traverse(structure):
              if check_duplicates and (name in out[module_name]):
                  previous = out[module_name][name]
                  if shaped(previous) != shaped(value):
                      raise ValueError(
                          "Duplicate array found with different shape/dtype for "
                          f"{module_name}.{name}: {fmt(previous)} vs {fmt(value)}."
                      )
              out[module_name][name] = value
      return data_structures.to_haiku_dict(out)
  
file_path: dm-haiku/haiku/_src/filtering.py
imports: import collections
  from collections.abc import Generator, Mapping, MutableMapping
  from typing import Any, Callable, TypeVar
  from haiku._src import data_structures
  from haiku._src import utils
  import jax
label_desc: Use image node_id 6 for calling a global function with example usage: merge() and returns: data_structures