new ChannelHeader()
        Channel header identifies the destination channel of the invocation
request and the type of request etc.
    
    
    
    
    
    
    
- MESSAGE = 0; // Used for messages which are signed but opaque
 - CONFIG = 1; // Used for messages which express the channel config
 - CONFIG_UPDATE = 2; // Used for transactions which update the channel config
 - ENDORSER_TRANSACTION = 3; // Used by the SDK to submit endorser based transactions
 - ORDERER_TRANSACTION = 4; // Used internally by the orderer for management
 - DELIVER_SEEK_INFO = 5; // Used as the type for Envelope messages submitted to instruct the Deliver API to seek
 - CHAINCODE_PACKAGE = 6; // Used for packaging chaincode artifacts for install
 
Properties:
| Name | Type | Description | 
|---|---|---|
type | 
            
            number | Any of the following:
 | 
        
version | 
            
            number | |
timestamp | 
            
            google.protobuf.Timestamp | The local time when the message was created by the submitter | 
channel_id | 
            
            string | Identifier of the channel that this message bound for | 
tx_id | 
            
            string | Unique identifier used to track the transaction throughout the proposal endorsement, ordering, validation and committing to the ledger | 
epoch | 
            
            number |