Optionalinit: HeadersInitinitial header values
Add a value to the list corresponding to a header
the name of the header
the value to add
Remove all values for a header
the name of the header
OptionalthisValue: unknownRetrieve a list of header values
the name of the header
a comma-separated list of values
Check if a value of a header has been set
the name of the header
true if the header has been set, false otherwise
Set or override the header value Both the key and the value have a limit of 32767 bytes
the name of the header
the new value
Create a new instance given initial header values.