'Update the property values as specified by keyword/value.
@param other: An object to update from.
@type other: (dict|L{Properties})
@return: self
@rtype: L{Properties}'

def update(self, other):

    if isinstance(other, Properties):
        other = other.defined
    for (n, v) in other.items():
        self.set(n, v)
    return self
