dropFirst abstract method
Drop the first count characters from the range.
Advances the start of the range to after the count first characters
of the range, or as many as are available if
there are fewer than count characters in the current range.
The count must not be negative.
If it is zero, the range is not changed.
Returns true if there are count characters in the range,
and false if there are fewer.
Implementation
bool dropFirst([int count = 1]);