How do I pass numbers to Java from karate? How do I call a Java constructor that takes a number?

I'm just trying to figure out how Java interop works in karate and looked at examples like here: https://www.swtestacademy.com/java-code-in-karate-api-tests/

My java class is this:

    import java.io.*;
    import java.lang.Process;
    public class Utils {
        double m_x;
    
        public Utils(double x) {
            m_x = x;
        }
    
        public static void main(String[] args) {
            System.out.println("Hello World");
        }
    
        public static int exec(String command) throws InterruptedException, IOException {
            Runtime run = Runtime.getRuntime();
            Process proc = run.exec(new String[]{"/bin/bash", "-c", command});
            proc.waitFor();
            return proc.exitValue();
        }
    
        public double nonStatic() {
            return m_x;
        }
    
        public double nonStatic1(double i) {
            return i+1;
        }
    }

I can call the static methods, but not the constructor or nonStatic methods. BTW, I know Java can handle function overloads, but I'm not sure about JavaScript, so that's why I use different function names.

One of my attempts to call the non-static functions is like this:

Scenario: nonStatic
* def nonStat =
"""
function() {
     var Utils = Java.type('Utils');
     var obj = new Utils(7.0);
     return obj.nonStatic();
}
"""
* def result = call nonStat
* print 'result', result

Scenario: nonStatic(int i)
* def nonStat1 =
"""
function(i) {
     var Utils = Java.type('Utils');
     var obj = new Utils(7.0)
     return obj.nonStatic1(i);
}
"""
* def result = call nonStat1 15
* print 'result1', result

I get: javascript function call failed: :3 TypeError: Can not create new object with constructor Utils with the passed arguments; they do not match any of its method signatures.

I had hoped that a JavaScript number would be converted to a double? The main function and exec function work. Both are static. I can get back a number, but fail at passing a number from karate/js to Java.

Thanks in advance for any help.