Importing slots has odd side effect of turning them into Types in python generator

[cmungall]

Minimal example, of a schema with one class and one slot "depth"

nmdc.py (imports mixs.yaml):

id: https://microbiomedata/schema

prefixes:
  biolinkml: https://w3id.org/biolink/biolinkml/
  
imports:
  - biolinkml:types
  - mixs
  
classes:

  biosample:
    slots:
      - depth
    slot_usage:
      depth:
        required: false

slots: {}

mixs.yaml:

id: https://microbiomedata/schema/mixs
slots:
  depth: {}

output:

$ pipenv run gen-py-classes schema/nmdc.yaml | grep -A2 -B2 'from includes.types'
Warning: default_range not specified. Default set to 'string'
from rdflib import Namespace, URIRef
from biolinkml.utils.curienamespace import CurieNamespace
from includes.types import Depth, String

metamodel_version = "1.4.3"

Note this line:

from includes.types import Depth, String

This of course causes an error as includes.types is from blml core, Depth is in our model

[cmungall]

OK, tracked down to here:

biolinkml/biolinkml/generators/pythongen.py

Lines 213 to 223 in 56295a9

	for slot in self.schema.slots.values():
	if not slot.imported_from:
	if slot.is_a:
	parent = self.schema.slots[slot.is_a]
	if parent.imported_from:
	rval.add_element(self.schema.slots[slot.is_a])
	if slot.domain:
	domain = self.schema.classes[slot.domain]
	if domain.imported_from:
	rval.add_element(self.schema.classes[slot.domain])
	add_slot_range(slot)

@hsolbrig may need help with the logic here