Check if the given value is boolean
@param {Object} v a value.
@return {Boolean} true if the given value is boolean
@method isBoolean
@for zebkit
963240
function isBoolean(o) {
    return o !== undefined && o !== null &&
          (typeof o === "boolean" || o.constructor === Boolean);
}
1295813
public Boolean asBooleanObj() {
		if (current == null)
			return null;
		if (current instanceof Boolean)
			return (Boolean) current;
		return null;
	}
293657
private boolean parseBoolean(String s) {
        if ( "1".equals(s) ) {
            return true;
        } else if ( "0".equals(s) ) {
            return false;
        } else {
            throw new IllegalArgumentException("Expected 1 or 0 for boolean value, was " + s);
        }
    }
444099
public boolean getBoolean(String key, boolean defaultValue) {
    Object value = get(key);
    if (value instanceof Boolean) {
      return (boolean) value;
    } else if (value instanceof String) {
      return Boolean.valueOf((String) value);
    }
    return defaultValue;
  }
1270598
public static boolean isBoolean(final String param) {
		if (isEmpty(param)) {
			return false;
		}
		return param.equalsIgnoreCase("true") || param.equalsIgnoreCase("false");
	}
647037
function assertBoolean(value, name, description) {
  if (!underscore.isBoolean(value)) {
    throw new Error(
        '<' + value + '> is not a boolean, ' + name + ': ' + description);
  }
}
927052
static boolean valueAsBoolean(Map<String, Object> map, Key key, boolean defaultValue) {
        return Boolean.parseBoolean(valueAsString(map, key, String.valueOf(defaultValue)));
    }
665168
function toBoolean(arg){
	if ( !arg ) return false;
	if ( typeof arg !== 'string' ) return true;
	return !/^(0|false|f|no|n)$/i.test((arg + '').trim());
}
50553
public boolean getBoolean(String key, boolean defaultValue) {
		addToDefaults(key, Boolean.toString(defaultValue));
		String value = get(key);
		if (value == null) {
			return defaultValue;
		} else {
			return Boolean.valueOf(value);
		}
	}
1156231
function toBoolean(value)
    {
        var result = { "true" : true, "false" : false }[value];
        return result == null ? value : result;
    }
1282401
function _isBlankNode(v) {
  // Note: A value is a blank node if all of these hold true:
  // 1. It is an Object.
  // 2. If it has an @id key its value begins with '_:'.
  // 3. It has no keys OR is not a @value, @set, or @list.
  var rval = false;
  if(_isObject(v)) {
    if('@id' in v) {
      rval = (v['@id'].indexOf('_:') === 0);
    }
    else {
      rval = (Object.keys(v).length === 0 ||
        !(('@value' in v) || ('@set' in v) || ('@list' in v)));
    }
  }
  return rval;
}
1135195
def asbool(value, true=(b'true', u'true'), false=(b'false', u'false')):
    
    value = value.strip().lower()
    if value in true:  # might raise UnicodeWarning/BytesWarning
        return True
    if value in false:
        return False
    raise TypeError()
571509
function bool(val) {
	assert(typeof val === 'boolean')
	var a = []
	a.op = 'bool'
	a.val = val
	return a
}
561182
public boolean getBoolean(String key, boolean defaultValue) {
		Object o = getObject(key);
		if (o == null) {
			return defaultValue;
		}
		boolean b = defaultValue;
		try {
			b = Boolean.parseBoolean(o.toString());
		}
		catch (Exception e) {
			throw new IllegalArgumentException("Object ["+o+"] associated with key ["+key+"] is not of type Boolean.");
		}
		return b;
	}
505866
def boolean(v):
    """"""
    if nodesetp(v):
        return len(v) > 0
    elif numberp(v):
        if v == 0 or v != v:
            return False
        return True
    elif stringp(v):
        return v != ''
    return v
8008
public boolean getBoolean(String key, boolean def) {
        Object tmp = objectMap.get(key);
        return tmp != null && tmp instanceof Boolean ? (Boolean) tmp : def;
    }
298325
public boolean getBoolean(String key, boolean defaultValue) {
    	String value = get(key);
    	if(value == null) return defaultValue;
   		return XType.getBoolean(value);
    }