j.l.c.MethodTypeDesc.dropParameterTypes throws the undocumented exception: IllegalArgumentException if start > end.
It's more natural to have the same behavior​ as dropParameterTypes in interface TypeDescriptor.OfMethod<ClassDesc,​MethodTypeDesc>:
Throws:
IndexOutOfBoundsException - if start is outside the half-open range [0, parameterCount), or end is outside the closed range [0, parameterCount], or if start > end