logback-android/src/main/java/ch/qos/logback/core/pattern/parser/Parser.java
Node Eopt() throws ScanException {
    // System.out.println("in Eopt()");
    Token next = getCurentToken();
    // System.out.println("Current token is " + next);
    if (next == null) {
      return null;
    } else {
      return E();
    }
  }
Node Eopt() throws ScanException {
    // System.out.println("in Eopt()");
    Token next = getCurentToken();
    // System.out.println("Current token is " + next);
    if (next == null) {
      return null;
    } else {
      return E();
    }
  }
Eopt = E|~