class Devise::ParameterFilter

def filter(conditions)
  conditions = stringify_params(conditions.dup)
  conditions.merge!(filtered_hash_by_method_for_given_keys(conditions.dup, :downcase, @case_insensitive_keys))
  conditions.merge!(filtered_hash_by_method_for_given_keys(conditions.dup, :strip, @strip_whitespace_keys))
  conditions
end