def add_constraints(constrs)
      ret = LPSolve.resize_lp(@ptr, @constraints.length + constrs.length,
                              @variables.length)
      fail if ret != 1

      constrs.each { |constr| store_constraint constr }
    end
def add_constraints(constrs)
      ret = LPSolve.resize_lp(@ptr, @constraints.length + constrs.length,
                              @variables.length)
      fail if ret != 1

      constrs.each { |constr| store_constraint constr }
    end
Add multiple constraints at once