Importing ABC directly from collections was deprecated from Python 3.4 and will be removed in 3.10

Importing ABC directly from collections was deprecated from 3.4 and will be removed in 3.10. Using collections.abc is recommended. Since the project is Python 3 only it doesn't require Python 2/3 shims for the fix.

rg "collections\.(Awaitable|Coroutine|AsyncIterable|AsyncIterator|AsyncGenerator|Hashable|Iterable|Iterator|Generator|Reversible|Sized|Container|Callable|Collection|MutableSet|Mapping|MutableMapping|MappingView|KeysView|ItemsView|ValuesView|Sequence|MutableSequence|ByteString)\b"

discussion/fun_mcmc/fun_mcmc_lib.py
291:      args, collections.Sequence) and not mcmc_util.is_namedtuple_like(args):
294:  elif isinstance(args, collections.Mapping):
332:  if not isinstance(ret, collections.Sequence) or len(ret) != 2:
373:  if not isinstance(ret, collections.Sequence) or len(ret) != 2:
434:  if not isinstance(ret, collections.Sequence) or len(ret) != 2:

discussion/nn/variational_base.py
65:  if isinstance(weights, collections.Mapping):

tensorflow_probability/python/distributions/mixture_same_family.py
206:        list(slices) if isinstance(slices, collections.Sequence) else [slices])

tensorflow_probability/python/distributions/distribution_properties_test.py
500:        tuple(slices) if isinstance(slices, collections.Sequence) else

tensorflow_probability/python/distributions/distribution.py
1503:  if (isinstance(x, collections.Sequence) and
1510:  if isinstance(x, collections.Mapping):

tensorflow_probability/python/distributions/joint_distribution_named.py
282:  return hasattr(x, '_asdict') or isinstance(x, collections.Mapping)

tensorflow_probability/python/distributions/independent.py
181:    slices = (tuple(slices) if isinstance(slices, collections.Sequence)

tensorflow_probability/python/internal/nest_util.py
78:  return (isinstance(args, collections.Sequence) and
84:  return isinstance(args, collections.Mapping) and not _force_leaf(args)

tensorflow_probability/python/distributions/joint_distribution_sequential.py
232:    if not isinstance(model, collections.Sequence):

tensorflow_probability/python/layers/distribution_layer.py
172:      value_is_seq = isinstance(d.dtype, collections.Sequence)

tensorflow_probability/python/distributions/internal/slicing.py
180:  if not isinstance(slices, collections.Sequence):

Start by running the provided rg command and inspect each reported file, including discussion/fun_mcmc/fun_mcmc_lib.py, tensorflow_probability/python/distributions/distribution.py, and the related test file. Update the deprecated collections ABC references consistently, then run the affected distribution tests and confirm the search no longer finds deprecated usages.