public ModuleDescriptor getModuleDescriptor(String moduleLabel)
			throws IllegalStateException {
		for (ModuleDescriptor descriptor : descriptors) {
			if (descriptor.getModuleLabel().equals(moduleLabel)) {
				return descriptor;
			}
		}
		throw new IllegalStateException(String.format(
				"Could not find module with label '%s' in the list of modules for " +
						"stream '%s': %s", moduleLabel, getName(), getModuleDescriptors()));
	}
Return the module descriptor for the provided label and type.

@param moduleLabel module label
@return module descriptor
@throws IllegalStateException if the requested module label and type
                              are not part of this stream
spring-xd-dirt/src/main/java/org/springframework/xd/dirt/core/Stream.java