F#: Fetching internal static type from a third party library returns null [duplicate]

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• Type.GetType(“namespace.a.b.ClassName”) returns null 16 answers

I am willing to fetch the type of the class below ExpressionCompiler:

namespace Marten.Util
{
  /// <summary>Compiles expression to delegate by emitting the IL directly.
  /// The emitter is ~20 times faster than Expression.Compile.</summary>
  internal static class ExpressionCompiler

I tried to use Type.GetType:

let expressionCompiler = Type.GetType("ExpressionCompiler")

or

let expressionCompiler = Type.GetType("Marten.Util.ExpressionCompiler")

But both of them return null