code: def as_interval_column(self, dtype):
      if isinstance(dtype, IntervalDtype):
          if isinstance(self.dtype, CategoricalDtype):
              new_struct = self._get_decategorized_column()
              return IntervalColumn.from_struct_column(new_struct)
          else:
              # a user can directly input the string `interval` as the dtype
              # when creating an interval series or interval dataframe
              if dtype == "interval":
                  dtype = IntervalDtype(
                      self.dtype.fields["left"], self.closed
                  )
              children = self.children
              return IntervalColumn(
                  size=self.size,
                  dtype=dtype,
                  mask=self.mask,
                  offset=self.offset,
                  null_count=self.null_count,
                  children=children,
                  closed=dtype.closed,
              )
      else:
          raise ValueError("dtype must be IntervalDtype")
  
file_path: cudf/python/cudf/cudf/core/column/interval.py
imports: from typing import Optional
  import pandas
  import pyarrow
  import cudf
  from cudf.core.column import StructColumn
  from cudf.core.dtypes import CategoricalDtype, IntervalDtype
label_desc: Use image node_id 7 for calling the IntervalColumn obj's underlying member method code with example usage: obj.as_interval_column(dtype) and returns: IntervalColumn, IntervalColumn