pyqgis - How to import for QgsVectorLayerJoinInfo in QGIS3 (python)?

I am trying to join layers programmatically following the answers in the GIS.SE question - Join table field with shapefile programatically (via PyQgis)? :

# Get input (csv) and target (Shapefile) layers
shp=iface.activeLayer()
csv=iface.mapCanvas().layers()[0]


# Set properties for the join
shpField='code'
csvField='codigo'
joinObject = QgsVectorJoinInfo()
#...

But I get an error about QgsVectorJoinInfo not defined. I tried (unsuccessfully) to import it with:

from qgis.core import QgsVectorJoinInfo

(because the documentation linked above says that QgsVectorJoinInfo is in the "core" library).

How should I import it properly or otherwise make the above code work?

(In general, how to tell from documentation which library to import?)

Answer

The class has been renamed from QgsVectorJoinInfo to QgsVectorLayerJoinInfo.

You now need to call each join function with their associated parameter:

#...
csvField = 'id'
shpField = 'ID'
joinObject = QgsVectorLayerJoinInfo()

joinObject.setJoinFieldName(csvField)
joinObject.setTargetFieldName(shpField)
joinObject.setJoinLayerId(csv.id())
joinObject.setUsingMemoryCache(True)
joinObject.setJoinLayer(csv)
shp.addJoin(joinObject)

Example: