How to use com.powsybl.iidm.network

private static void fillNodeOrBus(InjectionAdder adder, Terminal terminal) {
  if (terminal.getVoltageLevel().getTopologyKind() == TopologyKind.NODE_BREAKER) {
    adder.setNode(terminal.getNodeBreakerView().getNode());
  } else {
    if (terminal.isConnected()) {
      adder.setBus(terminal.getBusBreakerView().getBus().getId());
    }
    adder.setConnectableBus(terminal.getBusBreakerView().getConnectableBus().getId());
  }
}

private double getRho1(TwoWindingsTransformer twt) {
  double rho = twt.getRatedU2() / twt.getRatedU1();
  if (twt.getRatioTapChanger() != null) {
    rho *= twt.getRatioTapChanger().getCurrentStep().getRho();
  }
  if (twt.getPhaseTapChanger() != null) {
    rho *= twt.getPhaseTapChanger().getCurrentStep().getRho();
  }
  return rho;
}

private static boolean isMainComponent(LegBase<?> leg) {
  Bus bus = leg.getTerminal().getBusView().getBus();
  Bus connectableBus = leg.getTerminal().getBusView().getConnectableBus();
  boolean connectableMainComponent = connectableBus != null && connectableBus.isInMainConnectedComponent();
  return bus != null ? bus.isInMainConnectedComponent() : connectableMainComponent;
}

public Bus getBus(Terminal t, boolean noswitch) {
  if (noswitch) {
    return t.getBusView().getBus();
  } else {
    return t.getBusBreakerView().getBus();
  }
}

private static void checkRemovability(Substation substation, HvdcConverterStation station) {
  HvdcLine hvdcLine = substation.getNetwork().getHvdcLine(station);
  if (hvdcLine != null) {
    Substation s1 = hvdcLine.getConverterStation1().getTerminal().getVoltageLevel().getSubstation();
    Substation s2 = hvdcLine.getConverterStation2().getTerminal().getVoltageLevel().getSubstation();
    if ((s1 != substation) || (s2 != substation)) {
      throw createIsolationException(substation);
    }
  }
}

private double getPtcRho1(TwoWindingsTransformer twt, int p) {
  double rho1 = twt.getRatedU2() / twt.getRatedU1();
  if (twt.getRatioTapChanger() != null) {
    rho1 *= twt.getRatioTapChanger().getCurrentStep().getRho();
  }
  if (twt.getPhaseTapChanger() != null) {
    rho1 *= twt.getPhaseTapChanger().getStep(p).getRho();
  }
  return rho1;
}

private double getRtcRho1(TwoWindingsTransformer twt, int p) {
  double rho1 = twt.getRatedU2() / twt.getRatedU1();
  if (twt.getRatioTapChanger() != null) {
    rho1 *= twt.getRatioTapChanger().getStep(p).getRho();
  }
  if (twt.getPhaseTapChanger() != null) {
    rho1 *= twt.getPhaseTapChanger().getCurrentStep().getRho();
  }
  return rho1;
}

private double getG1(TwoWindingsTransformer twt, boolean specificCompatibility) {
  return getValue(specificCompatibility ? twt.getG() / 2 : twt.getG(),
          twt.getRatioTapChanger() != null ? twt.getRatioTapChanger().getCurrentStep().getG() : 0,
          twt.getPhaseTapChanger() != null ? twt.getPhaseTapChanger().getCurrentStep().getG() : 0);
}

public static double getRatio(TwoWindingsTransformer twt) {
  double rho = twt.getRatedU2() / twt.getRatedU1();
  if (twt.getRatioTapChanger() != null) {
    rho *= twt.getRatioTapChanger().getCurrentStep().getRho();
  }
  return rho;
}

private static boolean isRegulating(TwoWindingsTransformer tfo) {
  if (tfo.getPhaseTapChanger() != null) {
    return tfo.getPhaseTapChanger().getRegulationMode() != PhaseTapChanger.RegulationMode.FIXED_TAP
        && tfo.getPhaseTapChanger().isRegulating();
  }
  if (tfo.getRatioTapChanger() != null) {
    return tfo.getRatioTapChanger().isRegulating();
  }
  return false;
}

private static int correntStepPosition(TwoWindingsTransformer tfo) {
  if (tfo.getPhaseTapChanger() != null) {
    return tfo.getPhaseTapChanger().getTapPosition();
  }
  if (tfo.getRatioTapChanger() != null) {
    return tfo.getRatioTapChanger().getTapPosition();
  }
  return 0;
}

public static double getX(TwoWindingsTransformer twt) {
  double x = twt.getX();
  if (twt.getRatioTapChanger() != null) {
    x *= 1 + twt.getRatioTapChanger().getCurrentStep().getX() / 100;
  }
  return x;
}

private static void createSwitch(VoltageLevel vl, String id, String name, SwitchKind kind, boolean retained, boolean open, boolean fictitious, int node1, int node2) {
  vl.getNodeBreakerView().newSwitch()
      .setId(id)
      .setName(name)
      .setKind(kind)
      .setRetained(retained)
      .setOpen(open)
      .setFictitious(fictitious)
      .setNode1(node1)
      .setNode2(node2)
      .add();
}

public static double getR(TwoWindingsTransformer twt) {
  double r = twt.getR();
  if (twt.getRatioTapChanger() != null) {
    r *= 1 + twt.getRatioTapChanger().getCurrentStep().getR() / 100;
  }
  return r;
}

public static double getB(TwoWindingsTransformer twt) {
  double b = twt.getB();
  if (twt.getRatioTapChanger() != null) {
    b *= 1 + twt.getRatioTapChanger().getCurrentStep().getB() / 100;
  }
  return b;
}

public static double getG(TwoWindingsTransformer twt) {
  double g = twt.getG();
  if (twt.getRatioTapChanger() != null) {
    g *= 1 + twt.getRatioTapChanger().getCurrentStep().getG() / 100;
  }
  return g;
}

private static void addBuses(Network network, ConnectedPower balanceMainCC, ConnectedPower balanceOtherCC) {
  for (Bus b : network.getBusBreakerView().getBuses()) {
    if (b.isInMainConnectedComponent()) {
      balanceMainCC.busCount++;
    } else {
      balanceOtherCC.busCount++;
    }
  }
}

private static double rho(Leg2or3 leg, double ratedU0) {
  double rho = ratedU0 / leg.getRatedU();
  if (leg.getRatioTapChanger() != null) {
    RatioTapChangerStep step = leg.getRatioTapChanger().getCurrentStep();
    if (step != null) {
      rho *= step.getRho();
    }
  }
  return rho;
}

private static double adjustedX(Leg2or3 leg) {
  double x = leg.getX();
  if (leg.getRatioTapChanger() != null) {
    RatioTapChangerStep step = leg.getRatioTapChanger().getCurrentStep();
    if (step != null) {
      x *= 1 + step.getX() / 100;
    }
  }
  return x;
}

private static double adjustedR(Leg2or3 leg) {
  double r = leg.getR();
  if (leg.getRatioTapChanger() != null) {
    RatioTapChangerStep step = leg.getRatioTapChanger().getCurrentStep();
    if (step != null) {
      r *= 1 + step.getR() / 100;
    }
  }
  return r;
}