android/guava/src/com/google/common/base/Preconditions.java
public static void checkArgument(boolean expression, @NullableDecl Object errorMessage) {
    if (!expression) {
      throw new IllegalArgumentException(String.valueOf(errorMessage));
    }
  }
public static void checkArgument(boolean expression, @NullableDecl Object errorMessage) {
    if (!expression) {
      throw new IllegalArgumentException(String.valueOf(errorMessage));
    }
  }
public static void checkArgument ( boolean expression , @ NullableDecl Object errorMessage ) { if ( ! expression ) { throw new IllegalArgumentException ( String . valueOf ( errorMessage ) ) ; } }
Ensures the truth of an expression involving one or more parameters to the calling method.

@param expression a boolean expression
@param errorMessage the exception message to use if the check fails; will be converted to a
string using {@link String#valueOf(Object)}
@throws IllegalArgumentException if {@code expression} is false
Ensures the truth of an expression involving one or more parameters to the calling method .