Provision additional lookup fields with CSOM

AddDependentLookup.cs

private void AddDependantLookup(List parentList, List targetList, Guid lookupFieldId, Field primaryLookupField, string displayName) 
{ 
    Field toField = parentList.Fields.GetById(lookupFieldId); 
    _clientContext.Load(toField); 
    _clientContext.Load(targetList); 
    _clientContext.ExecuteQuery(); 
    Field dependantField = targetList.Fields.AddDependentLookup(displayName, primaryLookupField, 
        toField.StaticName); 
    FieldLookup dependantFieldLookup = _clientContext.CastTo<FieldLookup>(dependantField); 
    dependantFieldLookup.LookupField = toField.StaticName; 
    dependantField.UpdateAndPushChanges(true); 
    _clientContext.Load(dependantField); 
    _clientContext.ExecuteQuery(); 
}