code: def execute(cls, ctx, op):
      if op.gpu:  # pragma: no cover
          raise NotImplementedError(
              "Does not support tree-based nearest neighbors on GPU"
          )
  
      a = ctx[op.input.key]
      tree = cls._tree_type(
          a,
          op.leaf_size,
          metric=op.metric,
          **(op.metric_params or dict()),
      )
      ctx[op.outputs[0].key] = tree
  
imports: import cloudpickle
  import numpy
  from ...core import Object, OBJECT_TYPE, OBJECT_CHUNK_TYPE, recursive_tile
  from ...serialization.serializables import KeyField, Int32Field, DictField, AnyField, BoolField
  from ...tensor.core import TensorOrder
  from ...utils import has_unknown_shape, tokenize
  from ..operands import LearnOperand, LearnOperandMixin, OutputType
label_desc: Use image node_id 9 for calling the TreeBase obj's underlying member method code with example usage: obj.execute(cls, ctx, op) without return types