A subscriber issues a FETCH_CANCEL message to a publisher indicating it is no
longer interested in receiving Objects for the fetch specified by 'Subscribe ID'.
The publisher SHOULD close the unidirectional stream as soon as possible.
The format of FETCH_CANCEL is as follows:
FETCH_CANCEL Message {
Type (i) = 0x17,
Length (i),
Subscribe ID (i)
}
-
Subscribe ID: Subscription Identifier as defined in Section 7.7.