mask

Title : mask
Usage : $obj->mask(10,40,'Z');
$obj->mask(10,40);
$obj->mask($bio_location_obj, 'Z');
$obj->mask($bio_location_obj);
Function: masks a sequence region by replacing the respective part with a
custom character. If the character is omitted, 'X' in case of
protein and 'N' in case of DNA/RNA alphabet is used to mask the
sequence region.
Returns : the object it was invoked on
Args : integer for start position
integer for end position
custom character to use for masking
OR
Bio::LocationI location for sequence region (strand NOT honored)
custom character to use for masking