Retrieve values from the node relaxation solution at the current node.
Only available when the
where member variable is equal to
GRB_CB_MIPNODE, and GRB_CB_MIPNODE_STATUS is equal
v: The variable whose value is desired.
The value of the specified variable in the node relaxation for the current node.
xvars: The list of variables whose values are desired.
len: The number of variables in the list.
The values of the specified variables in the node relaxation for the current node. Note that the result is heap-allocated, and must be returned to the heap by the user.