title: How to remove constraint in ORTools
body: <p>Is there any way to remove defined constraint from solver with out clearing solver and creating constraints from first?</p>
  
  <p>suppose my problem is to maximize sum of 3 variables which two constraints</p>
  
  <p>constraint1: variable 2 should be between 8 - 10</p>
  
  <p>constraint2: variable 3 should be between 5 - 10</p>
  
  <pre><code>from ortools.linear_solver import pywraplp
  
  solver = pywraplp.Solver('SolveIntegerProblem',
                         pywraplp.Solver.CBC_MIXED_INTEGER_PROGRAMMING)
  
  objective = solver.Objective()
  
  Variable[0] = solver.IntVar(0, 5, variable 0 )
  Variable[1] = solver.IntVar(0, 10, variable 1 )
  Variable[2] = solver.IntVar(0, 20, variable 2 )
  
  objective.SetCoefficient(Variable[0], 1)
  objective.SetCoefficient(Variable[1], 1)
  objective.SetCoefficient(Variable[2], 1)
  
  objective.SetMaximization() 
  
  constraints.append(solver.Constraint(8,10))
  constraints[0].SetCoefficient(variable[1],1) 
  
  constraints.append(solver.Constraint(5,10))
  constraints[1].SetCoefficient(variable[2],1)  
  </code></pre>
  
  <p>Now in the second time of running my code I want to remove constraint number 2, but I can not find any operation to do it and the only way is to clear solver and define constraint from first.</p>
  
  <p>In this semi code the number of constraints were limited but actually, in my real code the number of constraint are many and I can not define them from first.</p>