code: func (c *Ctrie) Insert(key []byte, value interface{}) {
  	c.assertReadWrite()
  	c.insert(&Entry{
  		Key:   key,
  		Value: value,
  		hash:  c.hash(key),
  	})
  }
docs: // Insert adds the key-value pair to the Ctrie, replacing the existing value if
  // the key already exists.