in get_collocates do not error out when collocates not loaded

Change-Id: Ieeb5298e9111ea34f28d073d4f9816d27859f668
diff --git a/src/DerekoVecs.jl b/src/DerekoVecs.jl
index b31eb2d..1cc86da 100644
--- a/src/DerekoVecs.jl
+++ b/src/DerekoVecs.jl
@@ -246,6 +246,9 @@
 end
 
 function get_collocates(dv::d2vmodel, node::Int64, max=200)::DataFrame
+    if isnothing(dv.cdb)
+        return DataFrame(w2=Int64[], f2=Int64[], raw=Int64[], pmi=Float64[], npmi=Float64[], llr=Float64[], lfmd=Float64[], md=Float64[], left_raw=Int64[], right_raw=Int64[], left_pmi=Float64[], right_pmi=Float64[], dice=Float64[], logdice=Float64[], ldaf=Float64[], window=Int32[], af_window=Int32[], collocate=String[])
+    end
     collocates = get_collocates(dv.cdb, node - 1, length(dv.vocab), max)
     df = DataFrame(collocates)
     df.w2 = map(x -> x + 1, df.w2)