code: public AnyValueMap getAsNullableMap(String key) {
  		Object value = getAsObject(key);
  		return value != null ? AnyValueMap.fromValue(value) : null;
  	}
docs: Converts map element into an AnyValueMap or returns null if conversion is not
  possible.
  
  @param key a key of element to get.
  @return AnyValueMap value of the element or null if conversion is not
  supported.
  
  @see #fromValue(Object)