static boolean numericType(char c) {
    c = Character.toLowerCase(c);
    return c == TYPE_BYTE
      || c == TYPE_SHORT
      || c == TYPE_INT
      || c == TYPE_LONG
      || c == TYPE_FLOAT
      || c == TYPE_DOUBLE;
  }
Return whether a character is a numeric type identifier.

@param c character to check
@return if a numeric type identifier
nbt/src/main/java/net/kyori/adventure/nbt/Tokens.java