How to share arguments ( pass & return in both direction) between closure and method like shown below groovy code?

Question

Groovy code: how to pass and return arguments or values

def method (int a, Closure c) {
    Query q = new Query()
    c.delegate = q
    c()
    //label 1: pass a to label 2 and get str from there 
}
class Query
{
    void key (String str) {
        //label 2: return str and get a to method label 1.
    }
}
method(5) {
    key "got"
}

How to get access on both labels in above shown groovy code.

I don't know how to use some keys like .call() return inside this closure.

Update 1:

def method (int a, Closure c) {
    Query q = new Query()
    c.delegate = q
    c.call(a)
    def str = q.str
    println str
}
class Query
{
    def str
    def a
    void key (String str) {
        this.str = str
        this.a=a
        println a
    }
}
method(5) {
    key "got"
}

Actual Output:

null
got

Expected Output:

5
got

How to solve this ?

Answer 1

How about something like

def method (int a, Closure c) {
    Query q = new Query()
    q.a = a
    c.delegate = q
    c.call()
    def str = q.str
    println str
}
class Query
{
    def str
    def a
    void key (String str) {
        this.str = str
        println a
    }
}
method(5) {
    key "got"
}