columns.grow(currentLength+1);
}
else
{
FormatableBitSet modifiedColumns=new FormatableBitSet(columns);
modifiedColumns.shrink(columns.getLength()-1);
// All the bits from 0 ... colPosition-2 are OK. The bits from
// colPosition to the end need to be shifted 1 to the left.
// The bit for colPosition-1 simply disappears from COLUMNS.
// ColumnPosition values count from 1, while bits in the
// FormatableBitSet count from 0.