Equivalient method overload why necessary?

Question

I browsed some JAVA code made by Google, and I found the ImmutableSet: http://google-collections.googlecode.com/svn/trunk/javadoc/com/google/common/collect/ImmutableSet.html

Answer 1

Performance. In order to call the E... version of the method, the caller must allocate a new array. The caller only has to push the args on the stack to call the other methods.