contract IOwnable {

    /// @dev Emitted by Ownable when ownership is transferred.
    /// @param previousOwner The previous owner of the contract.
    /// @param newOwner The new owner of the contract.
    event OwnershipTransferred(address indexed previousOwner, address indexed newOwner);

    /// @dev Transfers ownership of the contract to a new address.
    /// @param newOwner The address that will become the owner.
    function transferOwnership(address newOwner)
        public;
}
/*
 
 Copyright 2019 ZeroEx Intl.
 
 Licensed under the Apache License, Version 2.0 (the "License");
 you may not use this file except in compliance with the License.
 You may obtain a copy of the License at
 
 http://www.apache.org/licenses/LICENSE-2.0
 
 Unless required by applicable law or agreed to in writing, software
 distributed under the License is distributed on an "AS IS" BASIS,
 WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 See the License for the specific language governing permissions and
 limitations under the License.
 
 */
function transferOwnership(address newOwner)
    public;

/// @dev Transfers ownership of the contract to a new address.
/// @param newOwner The address that will become the owner.