First step
@When("I do something with a param '$parameter'")
public void func1(String str){}
Second step
@When("I do something with a param '$value'")
public void func2(String str){}

Current duplicate step identification mechanism relies on step type (WHEN and THEN here) and step pattern (I do something with a param '$parameter' and I do something with a param '$value') which is apparently not reliable way to do identification