'Create new export instance.
@param tag: name of the XML tag
@type  tag: str
@param attrs: dictionary of XML attributes for this export tag
@type  attrs: dict
@param str: string value contained by tag, if any
@type  str: str'

def __init__(self, tag, attrs, str):

    self.tag = tag
    self.attrs = attrs
    self.str = str
