code: def prepare_parameter_or_function(
      value: ConstantOrFunction,
      *,
      lower_bound: Optional[float] = None,
  ) -> ParameterOrFunction:
      if isinstance(value, Function):
          return value
      else:
          if lower_bound is None:
              return Parameter(value)
          else:
              return Parameter(value, transform=positive(lower_bound))
  
file_path: GPflow/gpflow/utilities/parameter_or_function.py
imports: from typing import Optional, Union
  import tensorflow
  from check_shapes import check_shapes
  from ..base import Parameter, TensorData, TensorType
  from ..functions import Function
  from .None import positive
label_desc: Use image node_id 1 for calling a global function with example usage: prepare_parameter_or_function(value) and returns: value, Parameter, Parameter