pub fn parent(&self) -> Option<Self> {
        let id = self.data.parent()?;
        let data = self.registry.span_data(id)?;
        Some(Self {
            registry: self.registry,
            data,
        })
    }
/// Returns a `SpanRef` describing this span's parent, or `None` if this
/// span is the root of its trace tree.
Returns a `SpanRef` describing this span's parent, or `None` if this
span is the root of its trace tree.
Returns a ` SpanRef ` describing this span ' s parent or ` None ` if this span is the root of its trace tree .
pub fn parent(&self) -> Option<Self> {
        let id = self.data.parent()?;
        let data = self.registry.span_data(id)?;
        Some(Self {
            registry: self.registry,
            data,
        })
    }
pub fn parent ( & self ) -> Option < Self > { let id = self . data . parent ( ) ? ; let data = self . registry . span_data ( id ) ? ; Some ( Self { registry : self . registry , data , } ) }
Returns a `SpanRef` describing this span's parent, or `None` if this
span is the root of its trace tree.
Returns a ` SpanRef ` describing this span ' s parent or ` None ` if this span is the root of its trace tree .
&self
&self