Constant PLAY 

pub const PLAY: &str = r#"<?xml version='1.0' encoding='utf-8'?>
<s:Envelope
    xmlns:s="http://schemas.xmlsoap.org/soap/envelope/"
    s:encodingStyle="http://schemas.xmlsoap.org/soap/encoding/">
  <s:Body>
    <u:Play xmlns:u="urn:schemas-upnp-org:service:AVTransport:1">
      <InstanceID>0</InstanceID>
      <Speed>1</Speed>
    </u:Play>
  </s:Body>
</s:Envelope>
"#;