Compiller Error 1137: Calling Static ToString Function from another class

test case:
package org.comp
{
public class ToStringImp
{
public static function toString(str:String):String
{
return str;
}
}
}

package org.comp
{
import org.apache.royale.events.EventDispatcher;
import org.apache.royale.events.IEventDispatcher;
public class CompError extends EventDispatcher
{
public function CompError(target:IEventDispatcher=null)
{
super(target);
}
override public function toString():String
{
//compiler message :
//1137: Incorrect number of arguments. Expected no more than 0
return ToStringImp.toString("some string value");
}
}
}

Start by compiling the two ActionScript classes shown in the issue and confirm the 1137 error on the static ToStringImp.toString call. Trace how the compiler resolves that call versus the overridden CompError.toString method; done means the testcase compiles and returns the supplied string.

Written by the indexing model from the issue text.