@Override
    public boolean equals(Object other) {
        if (other == this) return true;
        if ( ! (other instanceof HostSpec)) return false;

        return ((HostSpec)other).hostname.equals(this.hostname);
    }
Returns the requested resources leading to this host being provisioned, or empty if unspecified
config-provisioning/src/main/java/com/yahoo/config/provision/HostSpec.java