code: def add_function(self, name, ssa_func):
      if not isinstance(ssa_func, Function):
          raise ValueError("Only Function can be added to Program.")
      self.functions[name] = ssa_func
  
imports: from __future__ import print_function
  from __future__ import division
  from __future__ import absolute_import
  import logging
  import numpy
  import sympy
  from .None import types
  from .block import Function
  from .var import Var
  from .types.symbolic import k_used_symbols, k_num_internal_syms
  from coremltools.converters.mil.input_types import InputType
label_desc: Use image node_id 2 for calling the Program obj's underlying member method code with example usage: obj.add_function(name, ssa_func) without return types