in lib/aws-record/record/attributes.rb [545:554]
def _key_attributes(id, opts)
if opts[:hash_key] == true && opts[:range_key] == true
raise ArgumentError, 'Cannot have the same attribute be a hash and range key.'
elsif opts[:hash_key] == true
@keys.hash_key = id
elsif opts[:range_key] == true
@keys.range_key = id
end
end