No native modifier in Java method generation.

[sidneywang]

/// A Java modifier.
#[derive(Debug, PartialEq, Eq, PartialOrd, Ord, Clone, Hash)]
pub enum Modifier {
    /// default
    Default,
    /// public
    Public,
    /// protected
    Protected,
    /// private
    Private,
    /// abstract
    Abstract,
    /// static
    Static,
    /// final
    Final,
}