translateAlgebra does not include DatasetClause

[Lars-H]

The translateAlgebra function supports serializing a parsed SPARQL query as text. However, it does not include the DatasetClause of the parsed query.
For example:

from rdflib.plugins.sparql.algebra import translateAlgebra
from rdflib.plugins.sparql.processor import prepareQuery

query_obj = prepareQuery("SELECT ?s FROM <http://example.org/G1> { ?s ?p ?o .}")
print(translateAlgebra(query_obj))

yields

SELECT ?s{?s ?p ?o.}

That is, the FROM statement is missing.