class_docstr: Class for formatting data in xml using Python standard library
  modules: `xml.etree.ElementTree` and `xml.dom.minidom`.
code: def get_prefix_uri(self) -> str:
      uri = ""
      if self.namespaces:
          if self.prefix:
              try:
                  uri = f"{{{self.namespaces[self.prefix]}}}"
              except KeyError:
                  raise KeyError(
                      f"{self.prefix} is not included in namespaces"
                  )
          else:
              uri = f'{{{self.namespaces[""]}}}'
  
      return uri
  
imports: from __future__ import annotations
  import codecs
  import io
  from typing import TYPE_CHECKING, Any
  from pandas._typing import CompressionOptions, FilePath, ReadBuffer, StorageOptions, WriteBuffer
  from pandas.errors import AbstractMethodError
  from pandas.util._decorators import doc
  from pandas.core.dtypes.common import is_list_like
  from pandas.core.dtypes.missing import isna
  from pandas.core.shared_docs import _shared_docs
  from pandas.io.common import get_handle
  from pandas.io.xml import get_data_from_filepath, preprocess_data
label_desc: Use image node_id 4 for calling the LxmlXMLFormatter obj's underlying member method code with example usage: obj.get_prefix_uri() and returns: uri