Raw xml elements lack of some attributes (e.g. tail)

I need to parse an xml element that contains a text mixed with other elements:

<a>start<b/>end</a>

I tried to use a raw element typed field as it's described here: https://pydantic-xml.readthedocs.io/en/latest/pages/data-binding/raw.html, but it turned out that pydantic-xml cuts off some details. In the example above, element <b> has a tail "end", but after transformation it gets missed.

from lxml import etree
from pydantic_xml import BaseXmlModel, computed_element, element
from pydantic_xml.element.native import ElementT as Element

class Root(BaseXmlModel, tag="root", arbitrary_types_allowed=True):
    a_raw: Element = element("a")

    @computed_element
    def parse_raw_a(self) -> str:
        text_in_a = self.a_raw.text
        for child in self.a_raw.getchildren():
            text_in_a += str(child.tail)
        return text_in_a

def main():
    xml = """\
<root>
<a>start<b/>end</a>
</root>
"""

    root = etree.fromstring(xml)

    a_node = root.find("a")

    # Before tranformation
    text_in_a = a_node.text
    for node in a_node:
        text_in_a += str(node.tail)
    print("Text in a:", text_in_a)

    root_obj = Root.from_xml_tree(root)

    out = root_obj.to_xml(pretty_print=True, encoding="UTF-8")
    print(out.decode("utf-8"))

    # After transformation
    text_in_a = root_obj.a_raw.text
    for node in root_obj.a_raw:
        text_in_a += str(node.tail)
    print("Text in a after deserializaton:", text_in_a)

main()

Output:

Text in a: startend
<root>
  <a>start<b/></a>
  <parse_raw_a>startNone</parse_raw_a>
</root>

Text in a after deserializaton: startNone

(in the output xml and after deserialization, concatenated string is "startNone" instead of "startend". It happens because b.tail == None)

Environment

Python 3.10.12
pydantic==2.0.3
pydantic-xml==2.2.2
lxml==4.9.3

dapper91 / pydantic-xml

Raw xml elements lack of some attributes (e.g. tail) #118