Builds a =@ (optionally =@ <axis_name>) query fragment, treating
the prior vector's values as entries of an axis.
Value
A DafrQuery.
Examples
AsAxis()
#> <DafrQuery> =@
AsAxis("cell")
#> <DafrQuery> =@ cell
Axis("cell") |> LookupVector("donor") |> AsAxis()
#> <DafrQuery> @ cell : donor =@