topic*               (string)    name of the MQTT topic to publish
username             (string)    MQTT username
password             (string)    MQTT password
qos                  (number)    set the quality of service priority, defaults to '0'
keep_alive_interval  (duration)  keep-alive interval for MQTT connections in s,m,h,d
reconnect_interval   (duration)  reconnect interval for MQTT connections in s,m,h,d

                psi,
                resolveCalleeExpressionOfFunctionCall,
                resolveFragmentOfCall
            )
            // FIR does not resolve to a symbol for equality calls.
            is FirEqualityOperatorCall -> toKtCallInfo(psi)
            is FirSafeCallExpression -> selector.toKtCallInfo(
                psi,
                resolveCalleeExpressionOfFunctionCall,

_2016-02-06_

 *  New: WebSockets now defer some writes. This should improve performance for
    some applications.
 *  New: Override `equals()` and `hashCode()` in our new cookie class. This
    class now defines equality by value rather than by reference.
 *  New: Handle 408 responses by retrying the request. This allows servers to
    direct clients to retry rather than failing permanently.

 * that makes `java.net.URL` unusable for many things. It shouldn't be used as a [Map] key or in a
 * [Set]. Doing so is both inefficient because equality may require a DNS lookup, and incorrect
 * because unequal URLs may be equal because of how they are hosted.
 *
 * ### Equal URLs should be equal
 *

  repeated string categories = 7;

  // The hash value of the storage version, the version this resource is
  // converted to when written to the data store. Value must be treated
  // as opaque by clients. Only equality comparison on the value is valid.
  // This is an alpha feature and may change or be removed in the future.
  // The field is populated by the apiserver only if the
  // StorageVersionHash feature gate is enabled.