Editing the class below does not show any errors.

package javaapplication1;

import java.util.List;

public class Main {
    public void useList(List<String> strings) {
    }
    
    public void useList(List<Long> longs) {
    }

    public static void main(String[] args) {
    }
}

But compiling the class gives:
/xxx/NetBeansProjects/JavaApplication1/src/javaapplication1/Main.java:6: name clash: 
useList(java.util.List<java.lang.String>) and useList(java.util.List<java.lang.Long>) have the same erasure
    public void useList(List<String> strings) {
/xxx/NetBeansProjects/JavaApplication1/src/javaapplication1/Main.java:9: name clash: 
useList(java.util.List<java.lang.Long>) and useList(java.util.List<java.lang.String>) have the same erasure
    public void useList(List<Long> longs) {
2 errors