@Nullable
    static ToMapTerminal tryExtract(TerminalBlock tb, PsiMethodCallExpression call) {
      if (tb.getCountExpression() != null ||
          !isCallOf(call, JAVA_UTIL_MAP, "merge", "put", "putIfAbsent")) {
        return null;
      }
      PsiLocalVariable variable = extractQualifierVariable(tb, call);
      if (!hasLambdaCompatibleEmptyInitializer(variable)) return null;
      InitializerUsageStatus status = getInitializerUsageStatus(variable, tb.getStreamSourceStatement());
      return new ToMapTerminal(call, tb.getVariable(), variable, tb.getStreamSourceStatement(), status);
    }
@Nullable
    static ToMapTerminal tryExtract(TerminalBlock tb, PsiMethodCallExpression call)