Consider following examples:
//nested multi-declarations statement nested in anonymous class declarations
Object c = new C() { String a, b; };
//bad style of writing multiple statements in one line
Object d; String e, f;
These two examples would break the assumption of multiDeclRefactor that "the start line of multi-declarations statement does not has other statements on the same line".
Although above examples should be hopefully very rare to happen in real-world applications, multiDeclRefactor should be able to handle above cases correctly.