code: def test_validate_pipeline_falsy_input_present():
      pipe = Pipeline()
      pipe.add_component("comp", Double())
      assert pipe.run({"comp": {"value": 0}}) == {"comp": {"value": 0}}
  
imports: from typing import Optional
  import pytest
  from haystack.core.pipeline import Pipeline
  from haystack.core.component.types import Variadic
  from haystack.core.errors import PipelineValidationError
  from haystack.core.component.sockets import InputSocket, OutputSocket
  from haystack.core.pipeline.descriptions import find_pipeline_inputs, find_pipeline_outputs
  from haystack.testing.sample_components import Double, AddFixedValue, Sum, Parity
label_desc: Use image node_id 16 for calling a global function with example usage: test_validate_pipeline_falsy_input_present() without return types