def __init__(self, sym_shape, dtype=None, name=None):
        """
        A placeholder with a state wrapping a tensor.

        Parameters
        ----------
        sym_shape: list, tuple
            * shape of the tensor.
        dtype: type
            * types.float or other scalar builtin types.
        name: str
            * name of the placeholder
        """
        self.sym_shape = sym_shape
        if dtype is None:
            dtype = types.fp32
        self.dtype = dtype
        self.name = name
        self._infer_output_var()

        A placeholder with a state wrapping a tensor.

        Parameters
        ----------
        sym_shape: list, tuple
            * shape of the tensor.
        dtype: type
            * types.float or other scalar builtin types.
        name: str
            * name of the placeholder
        
coremltools/converters/mil/mil/program.py