Dear Galaxy Team,
I am trying to create my own visualization for a unique datatype but I cannot get past this error in the load.  Where is the ID tag assigned for my visualization?
Thanks
Bob

galaxy.datatypes.registry ERROR 2015-12-10 15:10:13,440 Error loading display application (/home/HM_galaxy/config/plugins/visualizations/heatmap/config/heatmap.xml): ID tag is required for a Display Application
Traceback (most recent call last):
File "/home/HM_galaxy/lib/galaxy/datatypes/registry.py", line 563, in load_display_applications
display_app = DisplayApplication.from_file( config_path, app )
File "/home/rbrown/HM_galaxy/lib/galaxy/datatypes/display_applications/application.py", line 253, in from_file
return cls.from_elem( parse_xml( filename ).getroot(), app, filename=filename )
File "/home/rbrown/HM_galaxy/lib/galaxy/datatypes/display_applications/application.py", line 257, in from_elem
att_dict = cls._get_attributes_from_elem( elem )
File "/home/rbrown/HM_galaxy/lib/galaxy/datatypes/display_applications/application.py", line 265, in _get_attributes_from_elem
assert display_id, “ID tag is required for a Display Application”
AssertionError: ID tag is required for a Display Application

The  /visualizations/heatmap/config/heatmap.xml  file it is complaining about is below and I have a template under /templates

<?xml version="1.0" encoding="UTF-8" ?>
<!DOCTYPE visualization SYSTEM "../../visualization.dtd">
<visualization name="heatmap">
<data_sources>
<data_source>
<model_class>HistoryDatasetAssociation</model_class>
<test type="isinstance" test_attr="datatype" result_type="datatype">text.chm</test>
<to_param param_attr="id">dataset_id</to_param>
</data_source>
</data_sources>
<params>
<param type="dataset" var_name_in_template="hda" required="true">dataset_id</param>
</params>
<template>heatmap.mako</template>
</visualization>