Function SCIPexprhdlrGetNBranchings 

pub unsafe extern "C" fn SCIPexprhdlrGetNBranchings(
    exprhdlr: *mut SCIP_EXPRHDLR,
) -> c_longlong

gets number of times branching candidates reported by of this expression handler were used to assemble branching candidates

that is, how often did we consider branching on a child of this expression