Provides interfaces for registering and implementing code inspections. To register inspections, a plugin should implement the {@link com.intellij.codeInspection.InspectionToolProvider} interface and return the list of inspection classes from the getInspectionClasses() method. An inspection is a class extending {@link com.intellij.codeInspection.LocalInspectionTool}. During background code analysis or when the "Inspect Code..." action is invoked,, IDEA calls the inspection to inspect individual files, classes, methods and fields, and if the inspection detects any problems, it returns an array of {@link com.intellij.codeInspection.ProblemDescriptor} classes reporting the problem. Each problem descriptor can return a list of {@link com.intellij.codeInspection.LocalQuickFix} classes, each of which represents an action which the user can invoke by pressing Alt-Enter in order to fix the problem detected by the inspection.