public static MethodCallExpression createMethodCall(Expression target, String methodName, Expression arguments) {
    MethodCallExpression result = new MethodCallExpression(target, methodName, arguments);
    // and https://github.com/spockframework/spock/issues/1200
    // and https://issues.apache.org/jira/browse/GROOVY-9651
    result.setImplicitThis(false);
    return result;
  }
Turns an argument list obtained from AstUtil.getArguments() into an Object[] array
suitable to be passed to InvokerHelper or SpockRuntime. The main challenge is
to handle SpreadExpression's correctly.
spock-core/src/main/java/org/spockframework/compiler/AstUtil.java