// These two have the same value
new String("test").equals("test") ==> true

// ... but they are not the same object
new String("test") == "test" ==> false

// ... neither are these
new String("test") == new String("test") ==> false

// ... but these are because literals are interned by
// the compiler and thus refer to the same object
"test" == "test" ==> true

// concatenation of string literals happens at compile time resulting in same objects
"test" == "te" + "st"  ==> true

// but .substring() is invoked at runtime, generating distinct objects
"test" == "!test".substring(1) ==> false