How to use the pyscipopt.linexpr.LinExpr function in PySCIPOpt

def __neg__(self):
        return LinExpr({v:-c for v,c in self.terms.items()})

def __mul__(self, other):
        if _is_number(other):
            f = float(other)
            return LinExpr({v:f*c for v,c in self.terms.items()})
        elif isinstance(other, LinExpr):
            terms = {}
            for v1, c1 in self.terms.items():
                for v2, c2 in other.terms.items():
                    v = tuple(sorted(v1 + v2))
                    terms[v] = terms.get(v, 0.0) + c1 * c2
            return LinExpr(terms)
        else:
            raise NotImplementedError

def __add__(self, other):
        terms = self.terms.copy()
        if isinstance(other, LinExpr):
            # merge the terms by component-wise addition
            for v,c in other.terms.items():
                terms[v] = terms.get(v, 0.0) + c
        elif _is_number(other):
            c = float(other)
            terms[CONST] = terms.get(CONST, 0.0) + c
        else:
            raise NotImplementedError
        return LinExpr(terms)

def quicksum(termlist):
    '''add linear expressions and constants much faster than Python's sum
    by avoiding intermediate data structures and adding terms inplace
    '''
    result = LinExpr()
    for term in termlist:
        result += term
    return result

def __le__(self, other):
        '''turn it into a constraint'''
        if isinstance(other, LinExpr):
            return (self - other) <= 0.0
        elif _is_number(other):
            return LinCons(self, ub=float(other))
        else:
            raise NotImplementedError

def __mul__(self, other):
        if _is_number(other):
            f = float(other)
            return LinExpr({v:f*c for v,c in self.terms.items()})
        elif isinstance(other, LinExpr):
            terms = {}
            for v1, c1 in self.terms.items():
                for v2, c2 in other.terms.items():
                    v = tuple(sorted(v1 + v2))
                    terms[v] = terms.get(v, 0.0) + c1 * c2
            return LinExpr(terms)
        else:
            raise NotImplementedError