docstr: Test simple motif embedding
docstr_tok: ["Test","simple","motif","embedding"]
code: def test_simple_motif_embedding(self):
      "Test simple motif embedding"
      params = {
          "motif_name": "TAL1_known4",
          "seq_length": 1000,
          "num_seqs": 30,
          "GC_fraction": 0.4,
      }
      sequences, embed = dc.molnet.simple_motif_embedding(**params)
      assert sequences.shape == (30,)
  
file_path: deepchem/deepchem/molnet/tests/test_dnasim.py
imports: import deepchem
  import unittest
label_desc: Use image node_id 3 for calling the TestDNASim obj's underlying member method code with example usage: obj.test_simple_motif_embedding() without return types