Make "ensembl_gene_id" default option for all import functions.

[itsyogeshd]

[SherryDong]

Could you list the functions ?

[itsyogeshd]

its db_preload() function also for get_IDtransfer() function, because of biomart update and older version of R, the function seems to fail with following error.

Error in UseMethod("filter_") : no applicable method for 'filter_' applied to an object of class "c('tbl_SQLiteConnection', 'tbl_dbi', 'tbl_sql', 'tbl_lazy', 'tbl')"

but this is solved via adding useCache = FALSE in getBM() function, may be we add this in the get_IDtransfer() function as well.