Function extract_property_value 

pub fn extract_property_value<'a>(
    data: &'a [u8],
    offset: usize,
    closing_tag: u8,
    property: PropertyIdentifier,
    boundaries: &[PropertyValueBoundary],
) -> Result<(&'a [u8], usize), Error>

Extract the encoded value of property that starts at offset, just inside the opening tag closing_tag, returning the value bytes and the offset past the matching closing tag.

boundaries lists what may follow the closing tag in the enclosing production. It is consulted only for an EVENT_PARAMETERS value in the pre-framing form, whose payload can hold octets that look like the closing tag.