What function of the Java Boolean class makes it act as a boolean in an if statement or expression [duplicate]

I presume if I write:

Boolean doIt; ... if (doIt) { doSomething();} 

There is some function in the Boolean class that gets called that returns a boolean that the if statement evaluates to decide to doSomething() or not. What is the name of that function so I can write a class like:

public class MagicBoolean { public boolean toBoolean() { // this is the function name I am looking for return true; } ... MagicBoolean doIt; ... if (doIt) { doSomething(); } // doIt.toBoolean() is implicitly called here 

and get the same effect. And, no I don't want to extend Boolean as the logic in toBoolean will be much more complex than checking a simple value and it may involve computation or it may be a memo-ized value, but I don't want the uses of that "value" to know or care. It's just a flag to tell them that the strategy being used wants them to do this (or that) at this particular time.