typo

Author: Oscar Smith

src/cache_utils.jl

@@ -1,7 +1,7 @@
 is_constant_cache(::OrdinaryDiffEqConstantCache) = true
 is_constant_cache(::OrdinaryDiffEqCache) = false
 is_constant_cache(::CompositeCache) = is_constant_cache(cache.caches[1])
-is_constant_cache(::DefaultCache{Cache1}) where {Cache1} = Cache1 isa OrdinaryDiffEqConstantCache
+is_constant_cache(::DefaultCache{Cache1}) where {Cache1} = Cache1 <: OrdinaryDiffEqConstantCache
 
 function DiffEqBase.unwrap_cache(integrator::ODEIntegrator, is_stiff)
     alg = integrator.alg