# File lib/devise/param_filter.rb, line 8
    def filter(conditions)
      conditions = stringify_params(conditions.dup)

      @case_insensitive_keys.each do |k|
        value = conditions[k]
        next unless value.respond_to?(:downcase)
        conditions[k] = value.downcase
      end

      @strip_whitespace_keys.each do |k|
        value = conditions[k]
        next unless value.respond_to?(:strip)
        conditions[k] = value.strip
      end

      conditions
    end