Creates an AtkAttributeSet which consists of the attributes explicitly set at the position offset in the text. start_offset and end_offset are set to the start and end of the range around offset where the attributes are invariant. Note that end_offset is the offset of the first character after the range. See the enum AtkTextAttribute for types of text attributes that can be returned. Note that other attributes may also be returned.
the character offset at which to get the attributes, -1 means the offset of the character to be inserted at the caret location.
the address to put the start offset of the range
the address to put the end offset of the range