def initialize(opt = {})
@reftarget = nil
@handlers = {}
@charset = opt[:charset] || XSD::Charset.xml_encoding_label
@default_encodingstyle = opt[:default_encodingstyle] || EncodingNamespace
@generate_explicit_type =
opt.key?(:generate_explicit_type) ? opt[:generate_explicit_type] : true
@elementformdefault = opt[:elementformdefault]
@attributeformdefault = opt[:attributeformdefault]
@use_numeric_character_reference = opt[:use_numeric_character_reference]
@indentstr = opt[:no_indent] ? '' : ' '
@buf = @indent = @curr = nil
end