How to use the soupsieve.css_parser.CSSParser.process_selectors function in soupsieve

'''
).process_selectors(flags=FLG_PSEUDO | FLG_HTML)
# CSS pattern for `:default` (must compile CSS_CHECKED first)
CSS_DEFAULT = CSSParser(
    '''
    :checked,

    /*
    This pattern must be at the end.
    Special logic is applied to the last selector.
    */
    html|form html|*:is(button, input)[type="submit"]
    '''
).process_selectors(flags=FLG_PSEUDO | FLG_HTML | FLG_DEFAULT)
# CSS pattern for `:indeterminate`
CSS_INDETERMINATE = CSSParser(
    '''
    html|input[type="checkbox"][indeterminate],
    html|input[type="radio"]:is(:not([name]), [name=""]):not([checked]),
    html|progress:not([value]),

    /*
    This pattern must be at the end.
    Special logic is applied to the last selector.
    */
    html|input[type="radio"][name][name!='']:not([checked])
    '''
).process_selectors(flags=FLG_PSEUDO | FLG_HTML | FLG_INDETERMINATE)
# CSS pattern for `:disabled`
CSS_DISABLED = CSSParser(
    '''
    html|*:is(input[type!=hidden], button, select, textarea, fieldset, optgroup, option, fieldset)[disabled],

# Precompile CSS selector lists for pseudo-classes (additional logic may be required beyond the pattern)
# A few patterns are order dependent as they use patterns previous compiled.

# CSS pattern for `:link` and `:any-link`
CSS_LINK = CSSParser(
    'html|*:is(a, area, link)[href]'
).process_selectors(flags=FLG_PSEUDO | FLG_HTML)
# CSS pattern for `:checked`
CSS_CHECKED = CSSParser(
    '''
    html|*:is(input[type=checkbox], input[type=radio])[checked], html|option[selected]
    '''
).process_selectors(flags=FLG_PSEUDO | FLG_HTML)
# CSS pattern for `:default` (must compile CSS_CHECKED first)
CSS_DEFAULT = CSSParser(
    '''
    :checked,

    /*
    This pattern must be at the end.
    Special logic is applied to the last selector.
    */
    html|form html|*:is(button, input)[type="submit"]
    '''
).process_selectors(flags=FLG_PSEUDO | FLG_HTML | FLG_DEFAULT)
# CSS pattern for `:indeterminate`
CSS_INDETERMINATE = CSSParser(
    '''
    html|input[type="checkbox"][indeterminate],
    html|input[type="radio"]:is(:not([name]), [name=""]):not([checked]),
    html|progress:not([value]),

html|input:is(
        :not([type]),
        [type=""],
        [type=text],
        [type=search],
        [type=url],
        [type=tel],
        [type=email],
        [type=password],
        [type=number]
    )[placeholder][placeholder!='']:is(:not([value]), [value=""]),
    html|textarea[placeholder][placeholder!='']
    '''
).process_selectors(flags=FLG_PSEUDO | FLG_HTML | FLG_PLACEHOLDER_SHOWN)
# CSS pattern default for `:nth-child` "of S" feature
CSS_NTH_OF_S_DEFAULT = CSSParser(
    '*|*'
).process_selectors(flags=FLG_PSEUDO)
# CSS pattern for `:read-write` (CSS_DISABLED must be compiled first)
CSS_READ_WRITE = CSSParser(
    '''
    html|*:is(
        textarea,
        input:is(
            :not([type]),
            [type=""],
            [type=text],
            [type=search],
            [type=url],
            [type=tel],
            [type=email],
            [type=number],

[type=search],
        [type=url],
        [type=tel],
        [type=email],
        [type=password],
        [type=number]
    )[placeholder][placeholder!='']:is(:not([value]), [value=""]),
    html|textarea[placeholder][placeholder!='']
    '''
).process_selectors(flags=FLG_PSEUDO | FLG_HTML | FLG_PLACEHOLDER_SHOWN)
# CSS pattern default for `:nth-child` "of S" feature
CSS_NTH_OF_S_DEFAULT = CSSParser(
    '*|*'
).process_selectors(flags=FLG_PSEUDO)
# CSS pattern for `:read-write` (CSS_DISABLED must be compiled first)
CSS_READ_WRITE = CSSParser(
    '''
    html|*:is(
        textarea,
        input:is(
            :not([type]),
            [type=""],
            [type=text],
            [type=search],
            [type=url],
            [type=tel],
            [type=email],
            [type=number],
            [type=password],
            [type=date],
            [type=datetime-local],
            [type=month],

*/
    html|input[type="radio"][name][name!='']:not([checked])
    '''
).process_selectors(flags=FLG_PSEUDO | FLG_HTML | FLG_INDETERMINATE)
# CSS pattern for `:disabled`
CSS_DISABLED = CSSParser(
    '''
    html|*:is(input[type!=hidden], button, select, textarea, fieldset, optgroup, option, fieldset)[disabled],
    html|optgroup[disabled] > html|option,
    html|fieldset[disabled] > html|*:is(input[type!=hidden], button, select, textarea, fieldset),
    html|fieldset[disabled] >
        html|*:not(legend:nth-of-type(1)) html|*:is(input[type!=hidden], button, select, textarea, fieldset)
    '''
).process_selectors(flags=FLG_PSEUDO | FLG_HTML)
# CSS pattern for `:enabled`
CSS_ENABLED = CSSParser(
    '''
    html|*:is(input[type!=hidden], button, select, textarea, fieldset, optgroup, option, fieldset):not(:disabled)
    '''
).process_selectors(flags=FLG_PSEUDO | FLG_HTML)
# CSS pattern for `:required`
CSS_REQUIRED = CSSParser(
    'html|*:is(input, textarea, select)[required]'
).process_selectors(flags=FLG_PSEUDO | FLG_HTML)
# CSS pattern for `:optional`
CSS_OPTIONAL = CSSParser(
    'html|*:is(input, textarea, select):not([required])'
).process_selectors(flags=FLG_PSEUDO | FLG_HTML)
# CSS pattern for `:placeholder-shown`
CSS_PLACEHOLDER_SHOWN = CSSParser(
    '''
    html|input:is(

[type=tel],
            [type=email],
            [type=number],
            [type=password],
            [type=date],
            [type=datetime-local],
            [type=month],
            [type=time],
            [type=week]
        )
    ):not([readonly], :disabled),
    html|*:is([contenteditable=""], [contenteditable="true" i])
    '''
).process_selectors(flags=FLG_PSEUDO | FLG_HTML)
# CSS pattern for `:read-only`
CSS_READ_ONLY = CSSParser(
    '''
    html|*:not(:read-write)
    '''
).process_selectors(flags=FLG_PSEUDO | FLG_HTML)
# CSS pattern for `:in-range`
CSS_IN_RANGE = CSSParser(
    '''
    html|input:is(
        [type="date"],
        [type="month"],
        [type="week"],
        [type="time"],
        [type="datetime-local"],
        [type="number"],
        [type="range"]
    ):is(

[type=month],
            [type=time],
            [type=week]
        )
    ):not([readonly], :disabled),
    html|*:is([contenteditable=""], [contenteditable="true" i])
    '''
).process_selectors(flags=FLG_PSEUDO | FLG_HTML)
# CSS pattern for `:read-only`
CSS_READ_ONLY = CSSParser(
    '''
    html|*:not(:read-write)
    '''
).process_selectors(flags=FLG_PSEUDO | FLG_HTML)
# CSS pattern for `:in-range`
CSS_IN_RANGE = CSSParser(
    '''
    html|input:is(
        [type="date"],
        [type="month"],
        [type="week"],
        [type="time"],
        [type="datetime-local"],
        [type="number"],
        [type="range"]
    ):is(
        [min],
        [max]
    )
    '''
).process_selectors(flags=FLG_PSEUDO | FLG_IN_RANGE | FLG_HTML)
# CSS pattern for `:out-of-range`

html|input:is(
        [type="date"],
        [type="month"],
        [type="week"],
        [type="time"],
        [type="datetime-local"],
        [type="number"],
        [type="range"]
    ):is(
        [min],
        [max]
    )
    '''
).process_selectors(flags=FLG_PSEUDO | FLG_IN_RANGE | FLG_HTML)
# CSS pattern for `:out-of-range`
CSS_OUT_OF_RANGE = CSSParser(
    '''
    html|input:is(
        [type="date"],
        [type="month"],
        [type="week"],
        [type="time"],
        [type="datetime-local"],
        [type="number"],
        [type="range"]
    ):is(
        [min],
        [max]
    )
    '''
).process_selectors(flags=FLG_PSEUDO | FLG_OUT_OF_RANGE | FLG_HTML)

def process_selectors(self, index=0, flags=0):
        """Process selectors."""

        return self.parse_selectors(self.selector_iter(self.pattern), index, flags)


# Precompile CSS selector lists for pseudo-classes (additional logic may be required beyond the pattern)
# A few patterns are order dependent as they use patterns previous compiled.

# CSS pattern for `:link` and `:any-link`
CSS_LINK = CSSParser(
    'html|*:is(a, area, link)[href]'
).process_selectors(flags=FLG_PSEUDO | FLG_HTML)
# CSS pattern for `:checked`
CSS_CHECKED = CSSParser(
    '''
    html|*:is(input[type=checkbox], input[type=radio])[checked], html|option[selected]
    '''
).process_selectors(flags=FLG_PSEUDO | FLG_HTML)
# CSS pattern for `:default` (must compile CSS_CHECKED first)
CSS_DEFAULT = CSSParser(
    '''
    :checked,

    /*
    This pattern must be at the end.
    Special logic is applied to the last selector.
    */
    html|form html|*:is(button, input)[type="submit"]
    '''
).process_selectors(flags=FLG_PSEUDO | FLG_HTML | FLG_DEFAULT)

# CSS pattern for `:enabled`
CSS_ENABLED = CSSParser(
    '''
    html|*:is(input[type!=hidden], button, select, textarea, fieldset, optgroup, option, fieldset):not(:disabled)
    '''
).process_selectors(flags=FLG_PSEUDO | FLG_HTML)
# CSS pattern for `:required`
CSS_REQUIRED = CSSParser(
    'html|*:is(input, textarea, select)[required]'
).process_selectors(flags=FLG_PSEUDO | FLG_HTML)
# CSS pattern for `:optional`
CSS_OPTIONAL = CSSParser(
    'html|*:is(input, textarea, select):not([required])'
).process_selectors(flags=FLG_PSEUDO | FLG_HTML)
# CSS pattern for `:placeholder-shown`
CSS_PLACEHOLDER_SHOWN = CSSParser(
    '''
    html|input:is(
        :not([type]),
        [type=""],
        [type=text],
        [type=search],
        [type=url],
        [type=tel],
        [type=email],
        [type=password],
        [type=number]
    )[placeholder][placeholder!='']:is(:not([value]), [value=""]),
    html|textarea[placeholder][placeholder!='']
    '''
).process_selectors(flags=FLG_PSEUDO | FLG_HTML | FLG_PLACEHOLDER_SHOWN)
# CSS pattern default for `:nth-child` "of S" feature