php-slim-psr7 1.6.0-2 (amd64 binary) in ubuntu lunar

 This library can be used with other libraries that are compatible
 with the PSR-7 standard.
 .
 PSR-7 is a set of common interfaces defined by PHP Framework Interop Group.
 These interfaces are representing HTTP messages, and URIs used for HTTP.
 This standard helps normalizing a request and handling a response.