// Ensure that the bias portion of vec is represented in vec.
// REVIEW: Is this really necessary?
protected void EnsureBiases(ref VBuffer <float> vec)
{
// REVIEW: Consider promoting this "densify first n entries" to a general purpose utility,
// if we ever encounter other situations where this becomes useful.
Contracts.Assert(vec.Length == BiasCount + WeightCount);
VBufferUtils.DensifyFirst(ref vec, BiasCount);
}