Facet configuration help

I have read the documentation but i cannot get it to work.

Currently i have this facet (sorry for it being a discord pic, i cannot upload here)
[pic](https://media.discordapp.net/attachments/908671108293754910/1483842011197870151/image.png?ex=69bc0f0f&is=69babd8f&hm=7babec2b192749d1f90f259da81cb9ada89a8777adcbe5ebd6edff054f730a0c&=&format=webp&quality=lossless)

with this config

`"th_httpinspireeceuropaeutheme-theme_tree.key": {
"terms": {
"field": "th_httpinspireeceuropaeutheme-theme_tree.key",
"size": 34
},
"meta": {
"decorator": {
"type": "icon",
"prefix": "fa fa-2x pull-left gn-icon iti-tn"
},
"orderByTranslation": true
}
},`

and

` "th_httpinspireeceuropaeumetadatacodelistPriorityDataset-PriorityDataset_tree.default": {
"terms": {
"field": "th_httpinspireeceuropaeumetadatacodelistPriorityDataset-PriorityDataset_tree.default",
"size": 100,
"order": {
"_key": "asc"
}
}
},
"th_httpinspireeceuropaeutheme-theme_tree.key": {
"terms": {
"field": "th_httpinspireeceuropaeutheme-theme_tree.key",
"size": 34
},
"meta": {
"decorator": {
"type": "icon",
"prefix": "fa fa-fw gn-icon iti-tn"
}
}
}`

but when the page loads, the icon class appends this url: http://rdfdata.eionet.europa.eu/inspirethemes/themes/7, ending like this

`class="ng-scope fa fa-2x pull-left gn-icon iti-http://rdfdata.eionet.europa.eu/inspirethemes/themes/7"`

which of course, doesnt show any icon, as it is appending that url, but in my config, there is no such expression to append anything, apart that as shown in the image, it doesnt even have a text.

Start by reproducing the facet configuration with the provided icon decorator and inspect how the facet value becomes part of the generated CSS class. Done means the configured icon class remains valid, the URL is not appended, and the facet displays its icon correctly.

Written by the indexing model from the issue text.