static bool fullEntryCompare(const MBoxEntry &a, const MBoxEntry &b)
{
return a.messageOffset() == b.messageOffset() &&
a.separatorSize() == b.separatorSize() &&
a.messageSize() == b.messageSize();
}
static bool lessThanByOffset( const MBoxEntry &left, const MBoxEntry &right )
{
return left.messageOffset() < right.messageOffset();
}