add missing has_tstop interface function

Fixes #486

Author: ChrisRackauckas

src/integrators/integrator_interface.jl

@@ -74,6 +74,9 @@ jac_iter(integrator::StochasticCompositeCache) = Iterators.flatten(jac_iter(c) f
   push!(integrator.opts.tstops, integrator.tdir * t)
 end
 
+DiffEqBase.has_tstop(integrator::SDEIntegrator) = !isempty(integrator.opts.tstops)
+DiffEqBase.first_tstop(integrator::SDEIntegrator) = first(integrator.opts.tstops)
+DiffEqBase.pop_tstop!(integrator::SDEIntegrator) = pop!(integrator.opts.tstops)
 
 function DiffEqBase.add_saveat!(integrator::SDEIntegrator,t)
   integrator.tdir * (t - integrator.t) < 0 && error("Tried to add a saveat that is behind the current time. This is strictly forbidden")

test/events_test.jl

@@ -104,3 +104,16 @@ cb = ContinuousCallback(condition2,affect2!,nothing);
 prob = SDEProblem(HM_neuron!,HM_noise!,x0,(0.0,1999.9),params);
 sol  = solve(prob,ImplicitEM(),reltol = 1e-4, abstol = 1e-6,dense = true,callback=cb);
 sol  = solve(prob,SKenCarp(),reltol = 1e-4, abstol = 1e-6,dense = true,callback=cb);
+
+using DiffEqCallbacks
+
+function f(du,u,p,t)
+  du[1] = p[1] -u[1]
+end
+
+function g(du,u,p,t)
+  du[1] = p[2]
+end
+
+sprob = SDEProblem(f,g,[1.0],(0.0,10.0),[1.0,0.1])
+sol = solve(sprob,ImplicitEM(),callback=PositiveDomain())