'Get encrypted administrator password for a Windows instance.
:type instance_id: string
:param instance_id: The identifier of the instance to retrieve the
password for.
:type dry_run: bool
:param dry_run: Set to True if the operation should not actually run.'

def get_password_data(self, instance_id, dry_run=False):

    params = {'InstanceId': instance_id}
    if dry_run:
        params['DryRun'] = 'true'
    rs = self.get_object('GetPasswordData', params, ResultSet, verb='POST')
    return rs.passwordData
