Replay flattening

[AntonioCarta]

No description provided.

[AntonioCarta]

a very hacky fix but should solve the performance issues that @AlbinSou and @AndreaCossu have noticed.

[ContinualAI-bot]

Oh no! It seems there are some PEP8 errors! 😕
Don't worry, you can fix them! 💪
Here's a report about the errors and where you can find them:

avalanche/benchmarks/utils/data.py:156:81: E501 line too long (83 > 80 characters)
avalanche/benchmarks/utils/flat_data.py:263:1: E302 expected 2 blank lines, found 1
avalanche/benchmarks/utils/flat_data.py:483:81: E501 line too long (85 > 80 characters)
tests/training/__init__.py:1:26: W292 no newline at end of file
tests/training/test_replay.py:15:81: E501 line too long (81 > 80 characters)
tests/training/test_replay.py:141:81: E501 line too long (81 > 80 characters)
tests/training/test_replay.py:165:1: E302 expected 2 blank lines, found 1
2       E302 expected 2 blank lines, found 1
4       E501 line too long (83 > 80 characters)
1       W292 no newline at end of file

[ContinualAI-bot]

Oh no! It seems there are some PEP8 errors! 😕
Don't worry, you can fix them! 💪
Here's a report about the errors and where you can find them:

avalanche/benchmarks/utils/data.py:158:81: E501 line too long (83 > 80 characters)
avalanche/benchmarks/utils/flat_data.py:263:1: E302 expected 2 blank lines, found 1
avalanche/benchmarks/utils/flat_data.py:483:81: E501 line too long (85 > 80 characters)
tests/training/__init__.py:1:26: W292 no newline at end of file
tests/training/test_replay.py:15:81: E501 line too long (81 > 80 characters)
tests/training/test_replay.py:141:81: E501 line too long (81 > 80 characters)
tests/training/test_replay.py:165:1: E302 expected 2 blank lines, found 1
2       E302 expected 2 blank lines, found 1
4       E501 line too long (83 > 80 characters)
1       W292 no newline at end of file

[coveralls]

Pull Request Test Coverage Report for Build 5257696792

• 61 of 68 (89.71%) changed or added relevant lines in 5 files are covered.
• No unchanged relevant lines lost coverage.
• Overall First build on replay-flattening at 72.543%

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Changes Missing Coverage	Covered Lines	Changed/Added Lines	%
avalanche/benchmarks/utils/flat_data.py	9	10	90.0%
avalanche/benchmarks/scenarios/new_classes/nc_scenario.py	2	4	50.0%
avalanche/benchmarks/utils/data.py	16	20	80.0%

Totals
Change from base Build 5255727820:	72.5%
Covered Lines:	16241
Relevant Lines:	22388

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💛 - Coveralls