A convenience function to check whether this plugin file has an extra data field with key
that among separated list of values includes value (works on single value lists too).
For example, when extra data in the plugin is `X-Schemes=https;http`, calling this function with "X-Schemes" as key and "http" as value will return true.
It is also safe to call this function when there is no such key in plugin info file. Use [
method@Clapper.EnhancerProxy.get_extra_data] if you need to know whether key exists.
| this | |
| key |
name of the data to lookup |
| value |
string to check for |
|
whether list named with |