code: def build(self):
      schema = {"type": "array"}
      if self.nullable:
          self.add_type_schema({"type": "null"})
  
      if self.has_default:
          schema["default"] = [self.to_struct(i) for i in self.default]
  
      schemas = [self.maybe_build(s) for s in self.schemas]
      if len(schemas) == 1:
          items = schemas[0]
      else:
          items = {"oneOf": schemas}
  
      schema["items"] = items
      return schema
  
imports: from __future__ import absolute_import
  from collections import defaultdict
  import six
  from .None import errors
  from .fields import NotSet
label_desc: Use image node_id 3 for calling the ListBuilder obj's underlying member method code with example usage: obj.build() and returns: schema