Defines the base class that represents the Sending Context of a request.

  Defines the base class that represents the Sending Context of a
request. The sending context provides access to information about
the runtime environment of the originator of a GIOP message. For example,
when a value type is marshalled on a GIOP Request message, the receiver
of the value type may need to ask the sender about the CodeBase for the
implementation of the value type.