in
		the font will return a virtual GID.   This is valid for GSUB and cmap
		tables. For SING glyphlets, the cmap table is used to specify Unicode
		values for virtual GI's used in GSUB/GPOS rules. If the gid N is requested
		and does not exist in the font, or the glyphname has the form glyphN
		and does not exist in the font, then N is used as the virtual GID.
		Else, the first virtual GID is assigned as 0x1000 -1; for subsequent new
		virtual GIDs, the next is one less than the previous.

		If ignoreDecompileErrors is set to True, exceptions raised in
		individual tables during decompilation will be ignored, falling
		back to the DefaultTable implementation, which simply keeps the
		binary data.

		If lazy is set to True, many data structures are loaded lazily, upon
		access only.  If it is set to False, many data structures are loaded
		immediately.  The default is lazy=None which is somewhere in between.
		)