Apply suggestions from code review

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Author: st--

src/approximations/nystrom.jl

@@ -9,7 +9,9 @@ function sampleindex(X::AbstractVector, r::Real)
     return S
 end
 
-@deprecate sampleindex(X::AbstractMatrix, r::Real; obsdim::Integer=defaultobs) sampleindex(vec_of_vecs(X; obsdim=obsdim), r) false
+@deprecate sampleindex(X::AbstractMatrix, r::Real; obsdim::Integer=defaultobs) sampleindex(
+    vec_of_vecs(X; obsdim=obsdim), r
+) false
 
 function nystrom_sample(k::Kernel, X::AbstractVector, S::Vector{<:Integer})
     Xₘ = X[S]
@@ -18,7 +20,9 @@ function nystrom_sample(k::Kernel, X::AbstractVector, S::Vector{<:Integer})
     return (C, Cs)
 end
 
-@deprecate nystrom_sample(k::Kernel, X::AbstractMatrix, S::Vector{<:Integer}; obsdim::Integer=defaultobs) nystrom_sample(k, vec_of_vecs(X; obsdim=obsdim), S) false
+@deprecate nystrom_sample(
+    k::Kernel, X::AbstractMatrix, S::Vector{<:Integer}; obsdim::Integer=defaultobs
+) nystrom_sample(k, vec_of_vecs(X; obsdim=obsdim), S) false
 
 function nystrom_pinv!(Cs::Matrix{T}, tol::T=eps(T) * size(Cs, 1)) where {T<:Real}
     # Compute eigendecomposition of sampled component of K