@Nullable
  public XBreakpoint<?> getMasterBreakpoint(@NotNull XBreakpoint<?> slave) {
    XDependentBreakpointInfo info = mySlave2Info.get(slave);
    return info != null ? info.myMasterBreakpoint : null;
  }
@Nullable
  public XBreakpoint<?> getMasterBreakpoint(@NotNull XBreakpoint<?> slave)