code: def test_len_after_deletions(self):
      m = SeparateChainingHashTable(10)
      m.put(1, 1)
      self.assertEqual(1, len(m))
      m.del_(1)
      self.assertEqual(0, len(m))
      m.put(11, 42)
      self.assertEqual(1, len(m))
  
imports: from algorithms.map import HashTable, ResizableHashTable, SeparateChainingHashTable, word_pattern, is_isomorphic, is_anagram, longest_palindromic_subsequence
  import unittest
label_desc: Use image node_id 4 for calling the TestSeparateChainingHashTable obj's underlying member method code with example usage: obj.test_len_after_deletions() without return types