PyFile:FStringBackslashBeforeExpression.py
  PyAssignmentStatement
    PyTargetExpression: s
      PsiElement(Py:IDENTIFIER)('s')
    PsiWhiteSpace(' ')
    PsiElement(Py:EQ)('=')
    PsiWhiteSpace(' ')
    PyStringLiteralExpression: foo{\ 42}bar
      PyFormattedStringElement
        PsiElement(Py:FSTRING_START)('f'')
        PsiElement(Py:FSTRING_TEXT)('foo')
        PyFStringFragment
          PsiElement(Py:FSTRING_FRAGMENT_START)('{')
          PsiErrorElement:expression expected
            PsiElement(Py:BACKSLASH)('\')
            PsiWhiteSpace(' ')
            PsiElement(Py:INTEGER_LITERAL)('42')
          PsiElement(Py:FSTRING_FRAGMENT_END)('}')
        PsiElement(Py:FSTRING_TEXT)('bar')
        PsiElement(Py:FSTRING_END)(''')