Simple Query Data Source

def qapi = api.queryApi()
def exprs = qapi.exprs()

def t1 = qapi.tables().dataSource("Gapminder")

return qapi.source(t1, [t1.Country, t1.Population, t1.Year],
        exprs.and(
                t1.Country.equal("Canada")
        )
)
        .stream { it.collect { it } }