def ignore( self, other ):
if isinstance( other, Suppress ):<EOL><INDENT>if other not in self.ignoreExprs:<EOL><INDENT>self.ignoreExprs.append( other.copy() )<EOL><DEDENT><DEDENT>else:<EOL><INDENT>self.ignoreExprs.append( Suppress( other.copy() ) )<EOL><DEDENT>return self<EOL>
Define expression to be ignored (e.g., comments) while doing pattern
           matching; may be called repeatedly, to define multiple comment or other
           ignorable patterns.