message: adding a few utilities to accelerator buffer
diff: @@ -95,6 +95,18 @@ public:
  measurements.push_back(measurement);
  }
  + virtual void appendMeasurement(const boost::dynamic_bitset<>& measurement, const int count) {
  + std::stringstream ss;
  + ss << measurement;
  + bitStringToCounts[ss.str()] = count;
  + for (int i = 0; i < count; i++) measurements.push_back(measurement);
  + return;
  + }
  +
  + double computeMeasurementProbability(const std::string& bitStr) {
  + return bitStringToCounts[bitStr] / measurements.size();
  + }
  +
  /**
  * Compute and return the expectation value with respect
  * to the Pauli-Z operator. Here we provide a base implementation
  @@ -189,6 +201,8 @@ protected:
  */
  std::vector<boost::dynamic_bitset<>> measurements;
  + std::map<std::string, int> bitStringToCounts;
  +
  /**
  * The name of this AcceleratorBuffer
  */
  