anchor.diff:  
       let Create specimen = SpecimenContext(builder).Resolve(specimen)
       
  +    /// Gets the <see cref="ISpecimenBuilder"/> which create instances if the
  +    /// public Query is an instance method.
       member this.Builder = builder
  -    
  +
  +    /// <summary>
  +    /// Verifies that the return value for a Property is not null.
  +    /// </summary>
  +    /// <param name="propertyInfo">The property to verify.</param>
       override this.Verify (propertyInfo : PropertyInfo) =
           if propertyInfo = null then 
               raise <| ArgumentNullException("propertyInfo")
  
positive.code: open System
  open System.Reflection
  
  type ReturnValueMustNotBeNullAssertion (builder) =
      inherit IdiomaticAssertion()
      
  
negative.code:         if (getMethod <> null) then 
              this.Verify(propertyInfo.GetGetMethod());
  
      /// <summary>
      /// Verifies that the return value for a method is not null.
      /// </summary>
      /// <remarks>
      /// <param name="methodInfo">The method to verify.</param>
      override this.Verify (methodInfo : MethodInfo) =
          if methodInfo = null then 
              raise <| ArgumentNullException("methodInfo")
  