[BUG] matched node in a sequence is returned as an array

[sk-]

Nodes matched in a sequence are for some reason returned as a list. See the code below where element is matched as a list, whereas int is not. Somewhat related to #337 .

libcst version: 0.3.7 (installed with pip)

import libcst.matchers as m
import libcst

node = libcst.parse_expression("[3]")
matcher = m.List(
    elements=[
        m.SaveMatchedNode(
            m.Element(value=m.SaveMatchedNode(m.Integer(value="3"), "int")),
            "element"
        ),
    ]
)
print(m.extract(node, matcher))

{'element': [Element(
    value=Integer(
        value='3',
        lpar=[],
        rpar=[],
    ),
    comma=MaybeSentinel.DEFAULT,
)], 'int': Integer(
    value='3',
    lpar=[],
    rpar=[],
)}