code: public static <K,V> V getAt(Map<K,V> self, K key) {
          return self.get(key);
      }
docs: Support the subscript operator for a Map.
  <pre class="groovyTestCase">def map = [a:10]
  assert map["a"] == 10</pre>
  
  @param self a Map
  @param key  an Object as a key for the map
  @return the value corresponding to the given key
  @since 1.0