Table results seems to contains a value with a empty binding

[rbkloss]

Example:
"select ?s, ?p, ?o from ?cs where {?s ?p ?o};" yield:

bindings: ["?s" "?p" "?o"]
Results: [{"" "0.9945627"^^type:float64 <<==== this has no proper binding key
"?o" "0.9945627"^^type:float64
"?p" ":child_score"@[]
"?s" /t</account/gaia/XXXX>}
]