[DOC] Improve Code Coverage in Merlin Models to X%

[bschifferer]

Describe the documentation you'd like

Inline Code Coverage of Merlin Models is around 40%. We should aim for X%.

Merlin Models:
============================ Coverage for /workspace/01_MerlinDev/62_DocStrings/models/merlin/ ============================
--------------------------------------------------------- Summary ---------------------------------------------------------

Name	Total	Miss	Cover	Cover%
datasets/synthetic.py	4	1	3	75%
datasets/advertising/criteo/dataset.py	5	3	2	40%
datasets/ecommerce/aliccp/dataset.py	4	2	2	50%
datasets/ecommerce/booking/dataset.py	5	1	4	80%
datasets/ecommerce/dressipi/dataset.py	3	2	1	33%
datasets/entertainment/movielens/dataset.py	7	4	3	43%
models/config/schema.py	11	6	5	45%
models/tf/loader.py	5	2	3	60%
models/tf/blocks/cross.py	7	5	2	29%
models/tf/blocks/dlrm.py	2	1	1	50%
models/tf/blocks/experts.py	19	12	7	37%
models/tf/blocks/interaction.py	13	8	5	38%
models/tf/blocks/mlp.py	8	6	2	25%
models/tf/blocks/optimizer.py	12	4	8	67%
models/tf/blocks/retrieval/base.py	15	9	6	40%
models/tf/blocks/retrieval/matrix_factorization.py	5	3	2	40%
models/tf/blocks/sampling/base.py	4	4	0	0%
models/tf/blocks/sampling/cross_batch.py	6	4	2	33%
models/tf/blocks/sampling/in_batch.py	7	5	2	29%
models/tf/core/aggregation.py	39	29	10	26%
models/tf/core/base.py	39	27	12	31%
models/tf/core/combinators.py	40	21	19	48%
models/tf/core/encoder.py	20	9	11	55%
models/tf/core/index.py	14	9	5	36%
models/tf/core/prediction.py	9	5	4	44%
models/tf/core/tabular.py	36	27	9	25%
models/tf/distributed/embedding.py	5	2	3	60%
models/tf/experimental/sample_weight.py	5	3	2	40%
models/tf/inputs/continuous.py	9	6	3	33%
models/tf/inputs/embedding.py	46	32	14	30%
models/tf/losses/base.py	1	1	0	0%
models/tf/metrics/evaluation.py	19	12	7	37%
models/tf/metrics/topk.py	25	15	10	40%
models/tf/models/base.py	62	34	28	45%
models/tf/models/utils.py	2	2	0	0%
models/tf/outputs/base.py	12	9	3	25%
models/tf/outputs/block.py	5	3	2	40%
models/tf/outputs/classification.py	15	10	5	33%
models/tf/outputs/contrastive.py	13	9	4	31%
models/tf/outputs/topk.py	13	5	8	62%
models/tf/outputs/sampling/base.py	10	7	3	30%
models/tf/outputs/sampling/in_batch.py	7	5	2	29%
models/tf/outputs/sampling/popularity.py	5	3	2	40%
models/tf/prediction_tasks/base.py	22	16	6	27%
models/tf/prediction_tasks/classification.py	12	8	4	33%
models/tf/prediction_tasks/next_item.py	6	3	3	50%
models/tf/prediction_tasks/regression.py	5	3	2	40%
models/tf/prediction_tasks/retrieval.py	5	4	1	20%
models/tf/transformers/block.py	16	7	9	56%
models/tf/transformers/transforms.py	23	14	9	39%
models/tf/transforms/bias.py	17	13	4	24%
models/tf/transforms/features.py	50	36	14	28%
models/tf/transforms/noise.py	5	4	1	20%
models/tf/transforms/regularization.py	3	2	1	33%
models/tf/transforms/sequence.py	48	23	25	52%
models/tf/transforms/tensor.py	5	4	1	20%
models/tf/utils/batch_utils.py	8	5	3	38%
models/tf/utils/repr_utils.py	5	5	0	0%
models/tf/utils/search_utils.py	3	3	0	0%
models/tf/utils/testing_utils.py	11	7	4	36%
models/tf/utils/tf_utils.py	24	15	9	38%
models/torch/losses.py	2	1	1	50%
models/torch/block/base.py	19	14	5	26%
models/torch/block/mlp.py	4	4	0	0%
models/torch/features/base.py	1	1	0	0%
models/torch/features/continuous.py	4	3	1	25%
models/torch/features/embedding.py	15	10	5	33%
models/torch/features/tabular.py	4	1	3	75%
models/torch/model/base.py	32	24	8	25%
models/torch/model/prediction_task.py	6	6	0	0%
models/torch/tabular/aggregation.py	13	9	4	31%
models/torch/tabular/base.py	29	15	14	48%
models/torch/tabular/transformations.py	9	7	2	22%
models/torch/utils/data_utils.py	14	9	5	36%
models/torch/utils/torch_utils.py	20	14	6	30%
models/utils/dataset.py	7	4	3	43%
models/utils/dependencies.py	4	4	0	0%
models/utils/doc_utils.py	1	1	0	0%
models/utils/misc_utils.py	9	4	5	56%
models/utils/nvt_utils.py	1	1	0	0%
models/utils/registry.py	19	12	7	37%
models/utils/schema_utils.py	12	9	3	25%
-------------------------------------------------------------	--------------	-------------	--------------	---------------
TOTAL	1172	692	480	41.0%
-------------------------------------------------------------------------------------------------------------------------
(16 of 98 files omitted due to complete coverage)