[M B Nm] Class names should start with an upper case letter [NM_CLASS_NAMING_CONVENTION]
Class names should be nouns, in mixed case with the first letter of each internal word capitalized. Try to keep your class names simple and descriptive. Use whole words-avoid acronyms and abbreviations (unless the abbreviation is much more widely used than the long form, such as URL or HTML).
JAVA里，类的首字母需要大写，这个不多说了。