Get import code block for a craft spec.

specstr, sktime/skbase compatible object specification

i.e., a string that executes to construct an object if all imports were present imports inferred are of any classes in the scope of all_estimators option 1: a string that evaluates to an estimator option 2: a sequence of assignments in valid python code,

with the object to be defined preceded by a “return” assignments can use names of classes as if all imports were present


python code consisting of all import statements required for spec imports cover object/estimator classes found as sub-strings of spec