code: def _binary_product(variables):
      
      multiplier, multiplicand, product = variables
  
      return BinaryQuadraticModel({multiplier: 0.0,
                                   multiplicand: 0.0,
                                   product: 3.0},
                                  {(multiplier, multiplicand): 1.0,
                                   (multiplier, product): -2.0,
                                   (multiplicand, product): -2.0},
                                  0.0,
                                  Vartype.BINARY)
docs: Create a bqm with a gap of 2 that represents the product of two variables.
  
      Args:
          variables (list):
              multiplier, multiplicand, product
  
      Returns:
          :obj:`.BinaryQuadraticModel`