Nodes of different colours represent the following:
Solid arrows point from a submodule to the (sub)module which it is
descended from. Dashed arrows point from a module or program unit to
modules which it uses.
Determines the MIME type of the image through file format. The
following file formats are recognised: GIF, JPEG, PNG, SVG. On
error, the string mime is allocated but empty.
Nodes of different colours represent the following:
Solid arrows point from a procedure to one which it calls. Dashed
arrows point from an interface to procedures which implement that interface.
This could include the module procedures in a generic interface or the
implementation in a submodule of an interface in a parent module.