do not claim inner / anonymous classes as indexable (we process them from top level class)
look for xml properties in files with xml file type only
no need to create strings of PsiFile's Text when we can avoid it or use charsequence
don't call toString() without need to avoid garbage
avoid easy garbage
java.util.ArrayList$Itr: 1,720,417,512 (1%) bytes in 71,684,063 (2%) objects (avg size 24 bytes)
	java.util.ArrayList.iterator: 1,720,392,864 (99%) bytes in 71,683,036 (99%) objects
		com.intellij.openapi.projectRoots.impl.ProjectJdkTableImpl.findJdk: 938,831,640 (54%) bytes in 39,117,985 (54%) objects
		com.intellij.openapi.editor.impl.ComplementaryFontsRegistry.getFontAbleToDisplay: 218,420,520 (12%) bytes in 9,100,855 (12%) objects