code: def to_constant(expression):
      
      value = simplify(expression)
      if isinstance(value, Expression) and value.taint:
          raise ValueError("Can not simplify tainted values to constant")
      if isinstance(value, Constant):
          return value.value
      elif isinstance(value, Array):
          if expression.index_max:
              ba = bytearray()
              for i in range(expression.index_max):
                  value_i = simplify(value[i])
                  if not isinstance(value_i, Constant):
                      break
                  ba.append(value_i.value)
              else:
                  return bytes(ba)
              return expression
      return value
docs: Iff the expression can be simplified to a Constant get the actual concrete value.
          This discards/ignore any taint