Choose an alias to authenticate the client side of an SSLEngine connection given the public key type and the list of certificate issuer authorities recognized by the peer (if any).

The default implementation returns null.

Parameters:

keyType     the key algorithm type name(s), ordered with the most-preferred key type first.

issuers     the list of acceptable CA issuer subject names or null if it does not matter which issuers are used.

engine     the SSLEngine to be used for this connection. This parameter can be null, which indicates that implementations of this interface are free to select an alias applicable to any engine.

Returns: the alias name for the desired key, or null if there are no matches.

`keyType`		the key algorithm type name(s), ordered with the most-preferred key type first.
`issuers`		the list of acceptable CA issuer subject names or null if it does not matter which issuers are used.
`engine`		the `SSLEngine` to be used for this connection. This parameter can be null, which indicates that implementations of this interface are free to select an alias applicable to any engine.