class BinData::Struct

def sanitize_fields(params)
  if params.needs_sanitizing?(:fields)
    fields = params[:fields]
    params[:fields] = params.create_sanitized_fields
    fields.each do |ftype, fname, fparams|
      params[:fields].add_field(ftype, fname, fparams)
    end
    field_names = sanitized_field_names(params[:fields])
    ensure_field_names_are_valid(field_names)
  end
end