code: func (m *Map) Delete(k ident.ID) {
  	hash := m.hash(k)
  	for entry, ok := m.lookup[hash]; ok; entry, ok = m.lookup[hash] {
  		if m.equals(entry.key.key, k) {
  			m.removeMapKey(hash, entry.key)
  			return
  		}
  		// Linear probe to "next" to this entry (really a rehash)
  		hash++
  	}
  }
docs: // Delete will remove a value set in the map for the specified key.