Tests

Use `similar` methods from `ArrayPartion` for `NamedArrayPartition` #105

Job	Run time
Tests (lts, Downstream) / Tests - Downstream	3m 29s
Tests (1, Core) / Tests - Core	2m 47s
Tests (1, Downstream) / Tests - Downstream	2m 28s
Tests (lts, Core) / Tests - Core	1m 28s
Tests (pre, Core) / Tests - Core	1m 37s
Tests (pre, Downstream) / Tests - Downstream	1m 1s
	12m 50s

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