core/src/main/java/com/orientechnologies/orient/core/db/OPartitionedDatabasePool.java
public Object setProperty(final String iName, final Object iValue) {
    if (iValue != null) {
      return properties.put(iName.toLowerCase(Locale.ENGLISH), iValue);
    } else {
      return properties.remove(iName.toLowerCase(Locale.ENGLISH));
    }
  }
public Object setProperty(final String iName, final Object iValue) {
    if (iValue != null) {
      return properties.put(iName.toLowerCase(Locale.ENGLISH), iValue);
    } else {
      return properties.remove(iName.toLowerCase(Locale.ENGLISH));
    }
  }
Sets a property value

@param iName  Property name
@param iValue new value to set

@return The previous value if any, otherwise null