class RuboCop::Cop::Lint::DuplicateRegexpCharacterClassElement

def interpolation_locs(node)
  @interpolation_locs ||= {}
  # Cache by loc, not by regexp content, as content can be repeated in multiple patterns
  key = node.loc
  @interpolation_locs[key] ||= node.children.select(&:begin_type?).map(&:source_range)
end